Monday, October 31, 2011

Is it possible to convert a film SLR to digital?

Question

This may well be a question to which the answer is "can't be done," but I was wondering whether it was possible to convert a film SLR to a DSLR by putting a sensor in place of the film. I have a bunch of old bodies and lenses which I would love to be able to use, but I just don't want to mess around with film, so I was wondering whether it's possible to convert them to take digital images.

Answer

This has certainly been done with medium format SLRs that have interchangeable backs (e.g., Leaf and Phase One backs).

For a 35mm camera, the situation isn't nearly so positive. There was once a company that claimed to be working on a digital sensor that would be shaped like a 35mm film cannister with the sensor sticking out roughly like the film tongue. I'm reasonably certain they never produced even a partially working prototype, and even more certain they never put a product onto the market. Personally, I rather doubt it could be done.

In any case, the market opportunity for such a product is mostly past -- the vast majority of people who want to shoot digital have given up on the idea and bought digital bodies. Most have upgraded at least once by now, so used digital bodies are fairly common and quite reasonably priced...

What is the quantative relation between flash guide number and ISO?

Question

I found that formula on the Internet:

Guide Number = (Shooting Distance * Aperture) ÷ ISO Sensitivity

Is it correct? If it is could someone please explain why ISO is related to guide number in this way. The formula in wikipedia article about guide number does not have ISO in it so I wanted to know if the one I found is the right one and why.

UPDATE: this formula should look like this

Guide Number = (Shooting Distance * f-number) ÷ ISO factor

See the answer for the details!

Answer

The formula you've given is incorrect, at least for "straight" values of ISO numbers. ISO is related to sensitivity in that each stop in increased ISO is the same as a single stop of increased aperture. That means that to get ISO 200 guide numbers from ISO 100 numbers, you multiply by sqrt(2), just as increasing aperture by that factor is one stop. Quadrupling the ISO doubles the guide number, and so on. Or, expressed the other way around in the equation, as in your formula: the guide number required for a given aperture and distance goes down by a factor of about 1.4 for every stop of increased ISO.

So, it works if you replace "ISO sensitivity" in your formula with something like "ISO factor", where:

ISO  100 = 1
ISO  200 = 1.4
ISO  400 = 2
ISO  800 = 2.8
ISO 1600 = 4
...

Note the familiar sequence of numbers — that's no coincidence.

How can I ensure proper color rendition with browsers on wide gamut displays?

Question

When editing for the web, everyone will recommend you to use sRGB, since a lot of browsers don't offer color management, and most browsers will interpret all images as being sRGB anyway.

This is correct for browsers used on normal gamut displays, which live in sRGB themselves.

Now enter wide gamut displays. These live in AdobeRGB color space, and to my dismay on a wide gamut display browsers without color management will interpret image data as being in AdobeRGB color space, too. What happens if sRGB image data is interpreted as AdobeRGB? The colors are off, too strong, it looks gaudy.

The problem even continues when using a browser with colormanagement like FireFox, but viewing pictures without embedded profile: the pictures will be interpreted as AdobeRGB instead of sRGB.

In short: since I got my wide gamut display flickr looks awful.

Any ideas how I get my browsers (Internet Explorer and FireFox) to use sRGB instead of AdobeRGB for color rendition as default?

I'm using Windows 7.

Funny thing, when I download the images to the local drive and use a file viewer to view them, the color is correctly interpreted as sRGB.

Answer

Unfortunately, there is nothing you can do that is practical. To get what you want, you have to set your system profile to sRGB.

The behavior of image color rendition for images with no attached profiles is undefined. Browsers don't guess what color space an image is in, if no profile is attached. The operating system handles that.

The proper way to get color rendition correctly, is to attach a profile to the image. Obviously flickr (and smugmug thumbnails) do not give you this option.

So you have two choices: one, set windows to use sRGB as your monitor profile; then all non-tagged images will look like sRGB, but tagged images will look like crap, and your color management will be wack.

Or, just deal with the fact that unmanaged images are the devil and there is nothing you can do about it.

Perhaps there is a firefox plugin that can auto attach a color profile, but outside of that, it's just a plain old suck that is known as color management.

I've had to deal with this same issue with Smugmug. My images all have attached sRGB profiles, so they look great (in color managed browsers), but thumbnails looks oversaturated. It's because the thumbs are autogenerated, and smugmug refuses to attach a color profile to them, because it doubles the size of the thumbnail. So the thumbs render in whatever the way the OS decides to render them.

What should a beginner look at in comparing two point & shoot cameras?

Question

My interest in photography grew over the last few days, and I finally decided get into this thing. My goal is to become a Nature/Wildlife & Fashion photographer some day.

Since I am total beginner at present, I don't plan on buying a new camera or DSLR. What I have at hand are these - - a Canon PowerShot A590 IS (8MP) and a FUJIFILM FinePix AV100 (12MP) Series camera (I know both are really basic and pretty old models).

I have read that shouldn't be worried about the "megapixels" of camera, so what should I look for?

For instance, the specs for the two cameras I have are here and here. The examples are for the purpose of you suggesting me what I should look for in a camera.

Please advise, which one would be better and why? (Again, I am just a beginner, and I'll purchase a DSLR as soon as I get some understanding of how it all works, and some confidence. Thanks.)

Answer

This is a good exercise, and there are some interesting differences between these models which are illustrative of things worth comparing.

  • Technology generations: The Fujifilm camera is from 2010 and the Canon model from two years earlier. Electronics continue their march of getting cheaper and faster, and in general newer models have an advantage — although this is most true in the midrange. At the high end, more expensive initial choices give cameras longer functional lives (and non-electronic benefits like better controls and better build aren't influenced by tech improvements); at the low-end, new models might "spend" the improved tech on lowering costs rather than increasing quality.
  • Image stabilization: The Canon camera in your example has a "real" optical stabilization system, while the Fujifilm camera says it has "Digital Image Stabilization" which is doublespeak-like industry code for "no image stabilization".
  • Sensor size: The Canon camera has a 1/2.5-inch type sensor, while the Fujifilm has a slightly bigger 1/2.3-inch sensor — this is about 15% more surface area, which in this case is not very significant. But in some cases, the sensor size can really make a difference.
  • Optics: Both models feature a relatively useful moderate zoom. There's no way to compare image quality from the specs, and that's something that's probably also worth looking into if you can. The Fujifilm has a more conservative 3× zoom range (which is usually better for image quality), and provides a more-useful slightly wider angle (but not by much). Since you have the cameras, some actual test shots would be useful.
  • Aperture: Related; the Canon camera opens up to f/2.6 at the wide end and f/5.5 at the long end of the zoom range. The Fujifilm is a third of a stop slower at the wide end, and similar at the telephoto end. (It doesn't zoom out as far so direct comparison isn't easy.) This is a more significant difference than the 15% sensor area, but it's also in this case pretty small. In some cameras, the difference is worth making a big deal about.
  • CHDK: There's nifty firmware hacks available for Canon P&S cameras, including this model; there's really nothing like it for other brands. That might be a way to make an older camera do some really cool new tricks.
  • Viewfinder: The Canon has one, the Fujifilm does not. This isn't a through-the-lens finder (it's basically a little tunnel of plastic optics) and so is less useful than the one on a DSLR, but it may still fit your photography better.
  • Control modes: Honestly, this is less useful on a small-sensor camera, but if you're learning about photography it's nice to be able to take more control. Neither camera offers "full manual", but the Canon offers shutter priority and aperture priority program modes, while the Fujifilm is auto-exposure only. (In fact, I'm not sure it even has EV compensation or exposure lock, which would be a big concern.)
  • Responsiveness: You can't really tell this from specs, but maybe can get it from reviews. Testing it yourself is of course great. There's several important things to look for: time it takes to go from off to ready, time it takes from shot to ready again, and lag between when you fully-press the shutter to actually taking the photo. Secondarily, a fast AF speed and at least moderate burst rate are nice.

Then there's control layout, build, and general feel. This varies model to model but the different brands do tend to fit some generalization. For example, in every Canon P&S camera I've used — including the high-end ones — zooming is very clearly a "stepped" operation. You press the zoom lever, and it goes from 35mm to 50mm to 85mm, or whatever sequence of pre-programmed points the camera offers. Fujifilm cameras still use a servomotor that works in the same way (with the exception of a few which have the great feature of using manual zoom lenses), but there are more steps and it feels smoother.

Whether this is a concern or bother to you is somewhat personal — as is the issue of control or feel in general, but for learning photography, you do want as many accessible controls as possible, and basically more buttons is better, because fiddling in menus is no good.

How durable are photographic canvas prints to moisture and humidity?

Question

I want to put photographic canvas prints on stretcher frames in my bathroom, how bad of an idea is this? Obviously it depends on how wet my bathroom is, but I would call it fairly typical, and it does have a fan that pulls air out and two doors. The canvas prints are typical of what you could get from mpix, prodpi, whcc, or canvas on demand.

My main question is around bonded canvas prints and durability.

Answer

Most canvas prints use inks similar to (or actually are) big name inkjet inks like Epson and Canon. Such inks are susceptible to moisture and gaseous toxins and the like. Its kind of tough to generalize the print so much...all of the print houses you've listed use different kinds of canvas and different kinds of inks, and none of them really clearly specify what those inks are or how long they will last (a couple seem to indicate 100+ years, but don't specify under what conditions you might get such a lifetime.)

While you may not notice any change in the short term (i.e. a few years), hanging any canvas print that is printed with anything outside of modern Giclee inks (which are incredibly durable and excellent for canvas) will most likely not have a particularly long lifetime...I would say at most a couple decades, and after a number of years you'll likely start to see some fading or color shift. Only under archival conditions, wherein humidity and air quality and light are all controlled within a specific range, can you hope to achieve 100-200 year longevity.

You might also want to consider a clear protective spray. There are a variety of them available, and I am not sure if some are better suited to canvas prints or not. Usually you just need to evenly spray on a coat of this stuff once a print has fully cured (usually a full day, so if you send it off to a lab it should be cured by the time it gets to you). The spray should give your canvas prints much greater durability in a bathroom environment. It should protect from direct water exposure (splashing from sink or shower), and help protect a bit longer from fading.

Is it normal for a Nikon lens to make noise when zooming in or out?

Question

I read a lot of reviews when buying Nikon D5100 but no where did I hear this. Check this video on youtube. When you zoom in/out you can clearly hear the lens itself. This is highly undesirable. Is it normal with any DSLR or with Nikons only? Is this a genuine flaw? Canon Guys, do you hear this zoom as well?

Answer

Noises on the camera, such as the zooming of a lens or even an IS/VR motor, are often picked up by on-camera microphones. That's the disadvantage of an on-camera microphone and isn't specific to this camera or the Nikon brand.

The solution is to use a better mic that's either mounted off-camera or is a shotgun-style mic on the hotshoe where it won't pick up camera noise.

Are there cameras which have only bodies, and no default attached lenses?

Question

Do the cameras exist which have only bodies, and no default attached lenses?

Example this camera has a default lens attached:
http://www.amazon.com/dp/B004J3V90Y/?tag=stackoverfl08-20

I would like to have a camera with absolutely no lens at all. Do such things exist?

Answer

Yes. You're looking for "Body Only" offerings. The same camera without any lens:

Canon T3i Body Only

Note that you must have something to attach to (or at least hold in front of) the camera; when used without any lens at all, the whole image will be a total blur with absolutely no focus whatsoever.

How can I assure proper color rendition with browsers on wide gamut displays?

Question

When editing for the web, everyone will recommend you to use sRGB, since a lot of browsers don't offer color management, and most browsers will interpret all images as being sRGB anyway.

This is correct for browsers used on normal gamut displays, which live in sRGB themselves.

Now enter wide gamut displays. These live in AdobeRGB color space, and to my dismay on a wide gamut display browsers without color management will interpret image data as being in AdobeRGB color space, too. What happens if sRGB image data is interpreted as AdobeRGB? The colors are off, too strong, it looks gaudy.

The problem even continues when using a browser with colormanagement like FireFox, but viewing pictures without embedded profile: the pictures will be interpreted as AdobeRGB instead of sRGB.

In short: since I got my wide gamut display flickr looks awful.

Any ideas how I get my browsers (Internet Explorer and FireFox) to use sRGB instead of AdobeRGB for color rendition as default?

I'm using Windows 7.

Funny thing, when I download the images to the local drive and use a file viewer to view them, the color is correctly interpreted as sRGB.

Answer

Unfortunately, there is nothing you can do that is practical. To get what you want, you have to set your system profile to sRGB.

The behavior of image color rendition for images with no attached profiles is undefined. Browsers don't guess what color space an image is in, if no profile is attached. The operating system handles that.

The proper way to get color rendition correctly, is to attach a profile to the image. Obviously flickr (and smugmug thumbnails) do not give you this option.

So you have two choices: one, set windows to use sRGB as your monitor profile; then all non-tagged images will look like sRGB, but tagged images will look like crap, and your color management will be wack.

Or, just deal with the fact that unmanaged images are the devil and there is nothing you can do about it.

Perhaps there is a firefox plugin that can auto attach a color profile, but outside of that, it's just a plain old suck that is known as color management.

I've had to deal with this same issue with Smugmug. My images all have attached sRGB profiles, so they look great (in color managed browsers), but thumbnails looks oversaturated. It's because the thumbs are autogenerated, and smugmug refuses to attach a color profile to them, because it doubles the size of the thumbnail. So the thumbs render in whatever the way the OS decides to render them.

Sunday, October 30, 2011

How can I assure proper color rendition with browsers on WideGamut-Displays?

Question

When editing for the web, everyone will recommend you to use sRGB, since a lot of browsers don't offer color management, and most browsers will interpret all images as being sRGB anyway.

This is correct for browsers used on normal gamut displays, which live in sRGB themselves.

Now enter wide gamut displays. These live in AdobeRGB color space, and to my dismay on a wide gamut display browsers without color management will interpret image data as being in AdobeRGB color space, too. What happens if sRGB image data is interpreted as AdobeRGB? The colors are off, too strong, it looks gaudy.

The problem even continues when using a browser with colormanagement like FireFox, but viewing pictures without embedded profile: the pictures will be interpreted as AdobeRGB instead of sRGB.

In short: since I got my wide gamut display flickr looks awful.

Any ideas how I get my browsers (Internet Explorer and FireFox) to use sRGB instead of AdobeRGB for color rendition as default?

I'm using Windows 7.

Funny thing, when I download the images to the local drive and use a file viewer to view them, the color is correctly interpreted as sRGB.

Answer

Unfortunately, there is nothing you can do that is practical. To get what you want, you have to set your system profile to sRGB.

The behavior of image color rendition for images with no attached profiles is undefined. Browsers don't guess what color space an image is in, if no profile is attached. The operating system handles that.

The proper way to get color rendition correctly, is to attach a profile to the image. Obviously flickr (and smugmug thumbnails) do not give you this option.

So you have two choices: one, set windows to use sRGB as your monitor profile; then all non-tagged images will look like sRGB, but tagged images will look like crap, and your color management will be wack.

Or, just deal with the fact that unmanaged images are the devil and there is nothing you can do about it.

Perhaps there is a firefox plugin that can auto attach a color profile, but outside of that, it's just a plain old suck that is known as color management.

I've had to deal with this same issue with Smugmug. My images all have attached sRGB profiles, so they look great (in color managed browsers), but thumbnails looks oversaturated. It's because the thumbs are autogenerated, and smugmug refuses to attach a color profile to them, because it doubles the size of the thumbnail. So the thumbs render in whatever the way the OS decides to render them.

What are the pros and cons of a video camera versus a DSLR that can take video?

Question

I have made a few short films and plan to get more serious about it, but professional digital video cameras are generally expensive and the recent line of beginner DSLRs which can take HD video like Canon 550D gets cheaper. I wonder what pros and cons of video DSLRs over traditional video cameras are and if I should buy a new DSLR for film-making if I have already had a DSLR (Nikon D50).

Answer

I tried to list the pros and cons in a vacuum (ie ignoring external factors). For example, handycams have much better mics than than dSLR's, however you have the option of using either a dedicated recording system, or a solid quality mic. So the mic is still a con, but it's easily mitigated.

Pros

  • Access to awesome lens lineup
  • Amazing low-light performance
  • Use existing equipment, instead of separate video hardware
  • Lighter travel
  • Great performance for low cost compared to dedicated video cameras.
  • AWESOME photo image quality
  • Lens based image stabilization
  • build format (this can be a con as well)
  • Familiarity with camera body
  • In the right hands, with the right accessories, produces professional results.
  • Depth of Field
  • Huge image sensor

Cons

  • Dedicated video cameras are designed for video
  • Auto focus
  • Video Format Support
  • Video File Size
  • Only flash media
  • Sensor overuse causing heating issues
  • built-in audio sucks
  • very few bells and whistles for video. Since camera bodies are first and foremost for photography, most features are geared towards still photos (bracketing, AEB, etc). Features that you expect from a dedicated video camera (stereo mic, video outputs galore, jog-scrolling, enhanced playback features, dub over, etc) may not be present
  • "Jello/Jelly" Motion Effect caused by the CMOS Sensor when panned quickly. Not all dSLR bodies exhibit this.
  • build format (this can be a pro as well)

Does the liquid effect in these photographs have a specific name?

Question

I aspire to become a fashion and wildlife photographer, and I am starting out in that mission today. Lucky me, and the first photographer whose works I came across is Jaroslav Wieczorkiewicz.

His photography involves (splashed) liquids dressing the models, stunning I must say. What an inspiration to start with. (And moreover, it doesn't involve photo-editing for the effects.) But I don't know what to call this.

Different terms were used, like "Water Angel", "Water illustration", or "Milk Illustration" (if milk is used), and etc. — but does this kind of photography have a specific name?

Examples:

source: http://www.flickr.com/photos/jaroslav/sets/72157626124758315/

Answer

Fashion For Walls

Similar photos have been done before such as by the ad agency TBWA for the "Fashion for Walls" campaign. In this case they used a combination of a real model, and a mannequin was switched out, and then they threw paint buckets at the mannequin. Then in post production the two were combined.

I wouldn't say that these photos don't "involve photo-editing for the effects" rather, they don't use computer generated imagery for the effect, they just post process multiple images together.

Milk & Water

For Jaroslav Wieczorkiewicz's work, details can be found at this stobist post here. The main idea is that he used very high speed capture to freeze the water on the black background.

Jaroslav points out that the most important aspect is the concept, beyond that the actual work of putting it all together is not as difficult.

I have not attended one of his workshops where he gives detailed step by step instructions on how to accomplish works such as MILK. From what I can tell his work is a composite of many water/milk thrown images and images that are of the models by themselves on black studio backgrounds. Mix that with very high speed shots and ultra fast strobes/lights and you have the main idea.

Information directly from Jaroslav on the "Playing with water shoot": Here

Fashion for Walls info: Here

How to avoid soft image at longest focal length with telephoto zoom lens?

Question

I have a Tamron 70 - 300mm lens. I have noticed that the best focus I can achieve at the 300mm setting is not as sharp as the focus I usually get at a lower setting. Is this a common problem? Is there any way to work around this? The camera I use is a Canon 1000D.

Answer

Every lens has a different sharpness. Some zooms are better at the beginning of the range, some in the middle, some at the end. Maybe yours isn't at its best on the end. Check online reviews, there sure be someone who noted that.

If not, some other things can be checked:

  • sharpness change depending on the aperture size. How is the sharpness when closing aperture two or 3 stops down? For example, going to f8 or f11 if your lens is max f4.
  • at 300mm and more, any move can produce a slight defocus. What speed are you shooting at? A basic rule is to use 1/zoom seconds. In your case, use a speed greater than 1/300 of a second.
  • back or front focus problem: if the back/front focus is not correct, you will lose focus while changing the zoom factor. If you don't know what I'm talking about, check with a pro. Most of the time you can't do anything about it on your own.

How do I tag multiple photos in Lightroom?

Question

I'm processing a batch of photos in Lightroom 3.2. They are all of a Fall nature, so I want to apply the "Fall" keyword to the lot (31 of them). When I select all of them (click, shift+click), then enter the keyword in the Keywording box (in Library view), "Fall" is only applied to the first image that I selected, not all of them.

I seem to recall this works in Bridge. Is there a different way to go about it in Lightroom?

Answer

When bulk tagging, you need to make sure you are in library mode, AND that you are selecting photos from the main grid, not the film strip. I think this is a bug in LR3, however if you select multiple photos from the film strip, and then try to tag them, the tagging does not always take. It usually applies to the first photo selected, but not the rest. There seems to be a threshold to this...if you select only a few images in the film strip, it may work, but more than say 8-10, and it usually does not.

Manual Tagging in Library

alt text

When selecting multiple images from the main grid in Library mode, bulk tagging works fine. Just remember to hit the enter (return) key in the keyword box before moving on to make certain the update is actually applied to all of the selected images. In my experience, bulk tagging in the grid has always worked, while bulk tagging from the film strip has been sketchy at best, and generally never seems to work.

Painting Tags in Library

alt text

An alternative mode of tagging is to use the library painter. It is a small spray paint can icon next to the view mode icons below the grid in Library mode. Selecting this, it defaults to Keywords. Just enter the keywords you want to add, then click on the images you wish to add the keywords to. You can either click each image individually, or click and grad the spray can over multiple images in a continuous stream to "paint" on the new keywords. Click the icon below the grid again to disable paint mode.

Saturday, October 29, 2011

How to shop for a lens filter?

Question

What should I consider when shopping for a lens filter?

I see filters that range from $15 to $115 and more. What are the differences between the $15 and the $115 filter?

I'm asking in the generic sense but if you need specifics, I'm looking to buy a UV filter and a polarizing filter for a Panasonic GF1 w/ 20mm pancake lens.

EDIT: I've read some of the other posts and some refer to multi-coating but doesn't explain what is this and why it matters. What I've gathered from reading related posts is that price is generally the only indication of quality in the case of choosing a filter. Is this right?

Answer

You are adding an extra layer of glass over your lens. You want to make it as good as you can afford, so as not to (substantially) alter the light entering the lens, except as you intended per the filtration. So what is "good"? This is the crux of the question because you know you wouldn't screw a filter made of shower glass onto your lens -- but how can you tell once they all look pretty much "good"?

The answer to that question is pretty much manufacturer reputation. The manufacturers at the high end use glass that is relatively free of irregularities and coat them uniformly. Less expensive filters may not be as reliable. Note the use of "may not be." I believe many of us, myself included, take it on faith that there might be a difference but have never seen so much as one pixel change attributable directly to a bad filter.

So... what to do? My recommendation is this:

  • Buy from the more reputable brands -- Hoya and Tiffen at the lower end, Zeiss and B+W at the higher end. The theory here is that if there were a distortion problem, it would probably not be with a filter from one of these better-recognized brands and they would be happy to take care of it if there were an issue.
  • Buy what you feel your lens merits. I have Canon L-Series lenses and I get B+W filters. Do I notice a difference? As I said, no. You might notice a subtle difference in how smoothly a circular polarizer rotates, but in large measure, nada.
  • Think about whether you will be stacking or replacing the filter. If stacking, you need a screw mount on the front; if replacing, you can go with a thin profile filter which may not matter for a 20mm lens, but thicker filters with wider angle lenses can cause vignetting and a bit more light bouncing around in the lens barrel. When I say thick, I mean the actual filter ring, not the glass.

Coated filters may reduce the amount of stray diffraction that results from an extra glass element. Look at your lens. It's coated, right? So you might expect that in a filter. Again, it's a small thing, but cumulative and eventually might -- just might -- affect image quality.

Having said all of that, I have to tell you there are a lot of pros out there who mistreat their filters. I mean smudges all over them. And they bring home the shots because of where they point the camera, not what kind of filter they have. I am not a fan of abusing equipment, but a great image will remain a great image even if you have slightly less than perfect optics.

What double-sided ink jet paper is best for printing fine-art photo books at home?

Question

I am planning to print my own photo books of my landscape and wildlife photography. I have a Canon PIXMA Pro9500 II pigment inkjet printer, and I have spent an extensive amount of time working with fine art papers (namely various photo-rag and other fully natural papers from Hahnemuhle, Museo, and Moab). I have not spent much time working with luster, gloss, or semi-gloss papers, and never spent any time working with double-sided papers.

I started a search, however most of them come up with the cheaper off-brand papers intended for the general home consumer market. I am curious if anyone has done any work printing fine-art photo books at home, especially on larger formats like 11x17 or 13x19. As far as specific questions go about the paper itself:

  • What type of paper works best for a photo book?
    • Some kind of ultra smooth semi gloss/luster?
    • Are natural fine-art papers viable for a book?
  • Are there any brands that make double-sided fine-art paper for inkjets up to 13x19" (A3+) size?
  • How is the gamut and dmax of such papers if they exist?
  • Do such papers work well with pigment inks like Canon Lucia or Epson UltraChrome?

Answer

Stick with what you know.

"Fine art" papers are lousy for production books (they tend to show signs of handling too quickly), but then inkjet prints in general are going to suffer from the same sorts of problems (a single slightly damp fingerprint will ruin the print). Take it as read that the book(s) you will be producing yourself are going to be getting the white glove treatment.

If you were getting the book printed in the normal way for a fine art book (on an offset litho press using hexachrome or a 12-colour process screen at around 200 lines), the printer would use a heavily-coated paper and probably do a varnish hit, leaving a glossy page. That's mostly done to achieve a large contrast range (the varnish helps considerably with the Dmax). If your printing process gives you what you want with a fine art paper, then you probably won't like the "same" print done on a luster/gloss paper -- the character of the tonality will be different in subtle ways even if you spend a lot of time, paper and ink calibrating a new paper profile. It's sort of like trying to paint the "same" picture using oils for one and acrylics for the other. If your "real" prints are the result of an end-to-end previsualisation process that includes fine art paper, then a glossy book wouldn't really be representative of your work.

That said, Moab, Canson and Crane (Museo) all make at least one double-sided 13x19" rag paper. (If Hahnemuhle does too, I couldn't find it.) If you can't find them anywhere handier to you, Vistek (which is sort of the pro photo Mecca here in Toronto) carries all of them; if nothing else, you can use that evidence to convince your local retailer that the stuff does, indeed, exist.

What are the differences between two generations of Canon EF-S 55-250mm f4-5.6 IS?

Question

I was going to buy Canon EF-S 55-250mm f4-5.6 IS lens from eBay. But I saw there is a another lens available as MK II with same focal lengths. I googled to find difference between above lenses, but there were no results for that.

Can anyone explain the difference between these two lenses? Something I noticed is that the MK II lens is priced a little bit higher than the other.

Answer

According to announcement, the mkII version is only a few months old (the original one was introduced in 2007). Compared to older one, it seems to have gotten only a cosmetic makeover - some writings have moved to other locations and the plastic seems different. It has been noted that some of the new design features, like painted mount marker instead of a moulded one, and one-color finish (which I consider nicer), are probably cheaper than the older design.

The UD glass and Canon Super Spectra coating touted in the announcement were actually already present in the original design.

Does anyone have any tips to make Lightroom run faster?

Question

I'm running Lightroom 2.6 on Windows XP and it runs painfully slow. Just navigating from one image to the next takes a few seconds.

What can I do to speed it up?

Answer

Don't let the catalogue grow too large.

Separating your pictures into several catalogues can bring a lot of speed.

For me the main waiting point is waiting for Lightroom to render the 1:1 previews - if I let Lightroom render those on import I can usually work faster.

Of course putting the catalogue on a fast hard disk (SSD) helps, too.

Will converting images to DNG improve post-processing performance in Lightroom?

Question

I would like to know if converting my RAW files to DNG will improve the overall speed of Lightroom. The most painful issue is that it takes between 5 and 10 seconds to get my 1:1 image rendered when I zoom on it. I should add that my LR is configured so that it creates the 1:1 preview during importing of the files.

I use a MacBook Pro, Canon's RAWs, Lighroom 3.2. Thanks :)

Answer

All image previews are stored as JPEG files of various sizes inside of a .lrprev file. The loading speed of the preview images will likely not change much if you switch to DNG. The benefit of DNG is that it is an open standard format, and can keep the metadata in the same file as the image data, which simplifies portability. On the flip side, you would incur not only the extra cost of generating 1:1 previews on import, but also converting from your native RAW to DNG raw.

You also have to consider that DNG stores image data in a specific way, using integer values for pixel data. That will generally work for most sensors, however there are some special sensors that use non-square bayer arrays, make use of extra luminance pixels, or might possibly use floating point numbers rather than integers to store individual pixel values. At the very least, if you convert to DNG, you should keep your original RAW images around.

What DPI should I resize my image to for best printing quality?

Question

And my apologies if this sounds a bit too basic but I can't get my head around this.

I have a digital image I took with my camera. 4000x3000 pixels, and GIMP claims that its resolution is 72x72 DPI.

I would like to print a thumbnail of this picture in the highest quality possible. What I was told is that the printer which is going to be used works optimally with images set for 300 DPI.

In the printed document, I would like my image to be exactly 166 pixels wide, or 3.32cm (as Microsoft Word sets it).

And now to the question: how do I calculate how to resize my 12MP image, so when I take that image and import it into my word processor, it will end up printing the best?

My initial thought was this: Since the image on paper is going to end up being 3.32cm wide (1.31"), I should resize my image to be 300x1.31 = 393 pixels wide and set its DPI headers to note "300x300".

However, I'm pretty clueless about photography in general so I'm afraid this sounds as if I'm smoking something cheap.

Am I missing anything?

Answer

When it comes to print, terms like DPI, resolution, PPI, etc. get thrown around without much care or concern as to what they truly mean. So, before I send you off to a more in-depth answer about DPI, PPI, resolution, and print, a quick summary:

  • DPI: Dots Per Inch
    • A 'dot' is a single element of a pixel
    • On a computer screen, a dot is a single 'sub-pixel' element, and may be red, green, or blue
    • On a print, a dot is a single droplet of ink expelled by the print head
  • PPI: Pixels Per Inch
    • A 'pixel' is the smallest element of an image, "PIcture ELement"
    • On a computer screen, every pixel is composed of three 'dots' or sub-pixels, one red, one green, one blue
    • On an ink jet print, every pixel is composed of numerous dots of varying ink colors, usually a mix of cyan, magenta, yellow, and black, although modern printers often have several other inks as well
    • On a dye sublimation print, every pixel is a single dot from a blend of varying in colors, such as cyan, magenta, yellow, and black.
  • Resolution: Variable meaning
    • Regarding an image, the resolution usually means the width and height of an image in pixels
    • Regarding a print, the resolution usually means the number of pixels in an inch (or cm, if you are from a country that uses metric.)
    • Regarding a computer screen, resolution usually means the width and height of the screen in pixels, but can also mean pixels per inch (i.e. 72ppi is the common "resolution" of the average LCD screen, while higher end screens often have a resolution of 100ppi.)

To answer the rest of your question, I've written up an extensive article here on Photo-SE that answers that question in great detail:

Friday, October 28, 2011

Why do I have a red dot in every photo?

Question

Every picture that I took today have a red dot on the same place in every photo. It looks like a monitor "pixel error". Is just the lens dirty or did something bad happen to my cam?

Here some samples. Best mode to detect the dot is download the picture in original size (click the (i) then download)

Answer

You're exactly right — it's the same thing as a monitor pixel error, but on your camera's sensor rather than on an LCD screen.

You can either fix it in post-processing (automatically, with many RAW-processing packages) or have it mapped out with the camera's firmware.

If you're lucky, your camera model includes a built-in feature to do that yourself in the field; failing that, it's almost always covered under warranty service.

Why did camera manufacturers create crop sensor cameras?

Question

Why did camera manufacturers create crop sensor cameras? Was there a business reason? Did they figure that crop sensor cameras are cheaper to manufacturer, which would in turn lower prices and make it easier to penetrate the amateur photography market?

I'm under the assumption that full frame cameras were created first and crop sensor cameras have come along only recently (relative the entire life of cameras).

Answer

There were economic reasons, but they were not about getting to amateur market; it was more like getting any market. The main merit seen in early digital photography was speed of delivery (no need to develop films), so news agencies were the first targets.

During the dawn of digital photography, a full frame sensor would have been enormously expensive to produce. The technology was just not ready to produce perfect silicon wafers of that size; even the smaller ones were the price of a really nice car (or a top-notch medium / large format system). The first commercially available dSLR, Kodak DCS (1991, a.k.a. DCS100), managed to sell 987 units (with 1.3MP 1.8 crop factor sensors, some of them monochrome) priced at $20k...$25k (almost a median US household income). Provided that most professional photographers were convinced (and correct) that digital image quality was significantly worse than film, the market would have been too small for full frame cameras at their enormous price.

The first FF dSLR, 6MP Contax N Digital, came 11 years later at $7000, a sixth of average US household income. 11MP Canon 1Ds was announced at $8k the same year.

Smaller sensors were (and still are) several times cheaper, and with the 1.5 or 1.6 crop factor, the quality difference was (and still is) not that big to justify the cost difference for most people. At the same time with 1Ds, APS-C Canon 10D was announced at only $2k.

How does commander mode on a Nikon camera body differ from commander mode a on SB-700 Speedlight?

Question

My Nikon D80 and new Nikon SB-700 both offer Commander mode. I have two questions:

  • When NOT in wireless mode (that is, when the flash is plugged into the hot shoe either directly or with a cable), is there any difference using commander mode on the body vs the off-camera flash?
  • When IN wireless mode, I am able to use both the pop-up flash and the SB-700 at the same time. Is there a difference here?
  • Does one take precedence over the other if I set both to commander mode?

Answer

The most significant difference is that the SB-700 can control flashes that are further away (it has more power and a zoom head) and can be swiveled towards a flash that is at your side. By turning the flash head you can also make sure not to spill controller signal on the scene. Of course, when you have several slave flashes at both sides of camera, you can't use the advantages of swiveling head.

When using the pop-up flash for controller, your SB-700 is free for using as a slave.

Cameras usually disable pop-up flash when there's a flash on hot shoe, so you can't use them both as commanders; is your camera different in this respect?

Does a flash work well with regular alkaline batteries?

Question

In doing research prior to purchasing my first flash for my DSLR system I have come across a wealth of information, including this post that outlined many great points in selecting the best rechargeable batteries for use with the flash unit.

Since I will use the flash unit in far between outings I was planing to use regular batteries at first. I am still trying to decide if rechargeable batteries are justified for my limited use situation.

Since I have loads of batteries laying around to run my 2 year old's toys, I always have them on hand. I know they are not cheap and to make a sound decision, I need to know how fast or how many flash cycles I can expect to get on a set of batteries.

To add some context, on a single night I can take anywhere from 500 to 1,000 photos. If half were to use flash would i last the night on a single set?

The flash I will probably purchase is either the Nikon speed light 600 or the new 700.

Answer

Nikon produces excellent manuals for their flashes, with a lot of great technical information (rivaled in this area only by Metz). The following is from the SB-600 User Manual, page 19:

Alkaline-manganese | 3.5 sec. | 200  / 6-30 sec.
Lithium            | 4.0 sec. | 400  / 7.5-30 sec.
Nickel             | 2.5 sec. | 180  / 6-30 sec.
NiCd (1000 mAh)    | 2.9 sec. |  90  / 4-30 sec.
Ni-MH (2000 mA)    | 2.5 sec. | 220  / 4-30 sec.

The first column is the type, followed by approximate time between full-power flashes (best case), followed by the number of flashes you can expect to get, followed by the typical recharge time.

Additionally, on a further chart, Nikon recommends recharging your NiCds or NiMHs when the recycling time drops to 10 seconds, whereas it's suggested to keep your alkalines until they're taking a full half a minute between flashes. (It's worth noting that they give the 10-seconds-then-trash recommendation for Lithium primary cells too.)

So, you can see that while Lithiums last longer, it's not so much more than NiMH that it's really going to be worth it except in extraordinary circumstances (like, no access to power for weeks).

The most important differentiator here, though, is the recycle time. It takes 50% more time to be ready to go again when using alkaline batteries. That alone is a reason to go with NiMH.

Also, if you're not going through batteries constantly, I highly recommend low-self-discharge NiMH batteries like Sanyo's Eneloops — normally, NiMH batteries drain significantly just sitting overnight, and these don't, so you can charge them up and have them ready to go.

What affordable lights should I use for a number of large, very bright light-boxes?

Question

I'm working on printing a number of large, very bright backlit prints.

I need lots of lights that are affordable since I'll be needing quite a number of 'em.

My other concern is color reproduction, so I need light sources with a CRI of 100 preferably. Any suggestions?

Answer

You're only going to get 100% CRI out of tungsten lights or special purpose fluorescent tubes. The tubes are going to be expensive, not to buy but to install seeing as you need special fittings with transformers, starters and chokes. You might be able to get a bulk discount on fittings designed for office buildings however the tubes are likely to be long to fit behind a print in any case.

The best you will get out of a CFL (compact fluorescent lamp) is about 90, though I've heard talk of higher. That may be good enough for you, it would certainly be cheap to run but the bulbs aren't cheap.

The final option is daylight balanced tungsten bulbs which will give you 100 CRI, will be cheap to buy if you can find them. Which country are you based in? The EU is quickly making it illegal to sell tungsten bulbs but you can still find them in quantity with some retailers (at least this was the case last time I looked). This option will be most expensive to run, however.

Thursday, October 27, 2011

High CPU usage when using Lightroom + Dual Monitor?

Question

Wasn't sure if I should ask this question here or at another part of stackexchange, but I figured there would be more people using Lightroom here.

I just purchased a second monitor and have noticed that when I combine the second monitor with Lightroom my CPU usage goes up way way high, more than 100%!

I am using:

Macbook Pro 2009 OSX Lion 10.7 Lightroom 3.3

Is there anyone else experiencing this? Thanks

Answer

The current version of Adobe Lightroom is 3.5, if you are on 3.3 I would first recommend updating to the 3.5 version.

The Macbook Pro mid-2009 13" model came with 2GB of ram standard, I would be worried that if you only have that installed, you are already at the minimum system requirements for Lightroom. To run Lightroom well I would personally recommend at least 4GB of ram, 8 if possible on a 64bit system. It is possible that your system may be trying to swap out physical memory with the swap file and that would increase your processor usage I believe.

Another question I have, is that you stated that your CPU usage is over 100%. What exactly is happening on your PC that has you concerned? Is the actual performance of Lightroom poor?

To help diagnose I would turn off all other applications after restarting the machine, and make sure it isn't an issue after a restart. This may help to find a memory leak within the application. If you are still having issues with Lightroom, I think your best bet is the Adobe Forums.

Is there a simple flash bracket which holds a flash securely?

Question

The flash bracket / umbrella swivel I'm using works just fine, but I'm a little nervous about the way the flash attaches. It's held in place by a combination of friction from screw on the side of the flash bracket itself plus friction from screwing down the wheel on my flash's shoe/foot mount.

the cold shoe in question
CowboyStudio Flash Shoe Holder Light Stand Mount

Since the bracket is metal and my flash is the older Metz 48 AF-1 design, with plastic foot, I feel a bit nervous about clamping too tightly. But if I don't, it seems like there's a risk of the flash just sliding right out either the front or back, especially if the bracket gets tilted.

Is there a better little cold-shoe product that's less scary? I'm not aware of anything which has the Pentax-specific locking pin slot (except this which is out for price), which would be a little comfort, but that's not necessarily the right approach either. It seems like there ought to be something where there's a secure latch on the front and back, so once mounted the flash can't go anywhere (but which could still be easily undone). I can't find it, though. This accessory shoe at least has the front blocked, which might be an improvement, but on the other hand it lacks the side friction screw.

Does what I'm looking for exist? (Ideally for under $20, shipped. I know geegaws like this end up being outrageously priced.)

Answer

Sheesh — how to find something I'm looking for: write up the question carefully on Stack Exchange, at which point the keywords to search for will be more clear in my mind, and i can quickly Google up the answer myself:

Frio Universal Cold Shoe Adapter. Looks exactly designed for what I need, and at $15 + $4 shipping it just squeaks under my price limit, too.


So I ordered one; here's the report!

Description

It's a little rectangular piece of relatively tough plastic, with a cold-shoe "pocket" near the front and a flexible clip to hold the flash in place. Underneath, there's a securely-attached metal socked, threaded for a standard 1/4" tripod screw.

enter image description here

Function

It works; my Metz flash snaps easily into place and is held there securely. Until I tighten the wheel on the flash shoe itself, it wobbles from side to side a bit but there's clearly no risk of the flash going anywhere. Once the wheel is tightened, it's steady.

The clip to release the flash is molded from the same piece of plastic; it flexes down or up to provide the locking. I didn't have any difficulty or frustration working it — in fact, it's easier and faster than the screw mechanism of my existing cold metal shoe. The clip seems secure and it does appear to be high quality plastic, but if you take your flash on and off the clip dozens of times a day, it may wear out.

The other thing worth mentioning is that since the screw doesn't go entirely through the clip, you may want a nut to tighten underneath the clip. It holds well enough without but that would feel even more secure and make it easier to fix the clip do it definitively faces one direction even if bumped.

Value

It's a little pricey for what it is, but that's typical for niche products for little companies. And when compared to the generally high prices for this kind of photo equipment in general, it actually seems within the realm of reason. Given that it seems to do its job so well, I'd say it's worth it for the ease of use and the security for my flash. You can get it with free shipping from Amazon, or get the triple-pack directly for $40 including shipping — get one for multiple light stands, or split with a friend.

Conclusion

Yep, this answers my question. I hope this or similar clips become standard, but until then, this'll do.

How does the lens diameter influence photo quality?

Question

I have tested two different 50mm lenses in my camera. One was a Nikkor 50mm ∅52mm. The other one was a Sigma 50mm ∅72mm. I took some pictures with both lenses using the same setup for aperture and shutter speed, but couldn't notice significant differences in the quality of the pictures.

So, how does the diameter affects the photo quality, if it does? What advantages would the ∅72mm lens have over the ∅52mm one?

Answer

It's not just about maximum aperture. Even in two lenses with the same focal length and max aperture, one could have a larger diameter. The larger diameter could be because of using larger lens elements, which could have advantages with regard to sharpness and light falloff at the edges of the image circle. Some lenses may even project a larger image circle than is strictly necessary. These difference would likely be more apparent at larger apertures (especially wide-open), if they are there at all.

Having said that you can't automatically assume the "larger" lens will always be better optically.

When is it OK to place the subject in the middle of a picture?

Question

When is it OK to place the subject in the middle of a picture?

I took this picture and feel very compelled to put the subject in the centre rather than on the sides.

picture

Answer

When is it OK to place the subject in the middle of a picture? Whenever you feel like it works best!

The general rule of not centering your subject is time-honored, and comes from one basic idea: the center of an image is a stable, straightforward place. When you put something there visually, it stays there visually, usually resulting in a static composition.

When you have your subject off-center, you can use tension and dynamic balance, which tend to make a more engaging composition.

Other factors can contribute to this: the lines from the subject's eyes and the way the subject is facing; color weight; other objects and motion in the composition and their balance. Overall, these can add dynamic interest even if your main subject is static.

You may, though, want the simple, straightforward, and more-static image. That's okay. Think about the flow of interest as you are observing the photo, and decide if a centered or dynamically-balanced composition fits your intent better.

In your particular example, the dog's face (and particularly eyes) aren't actually centered at all: they're quite towards the top of the frame. The overall subject is centered, but the face has considerable off-center visual weight. The leaves on the right side contrasting with the bright yellow flowers on the center-right provide some reason to keep the horizontal as it is; a tighter crop either cuts out the context of the plants or leaves the frame feeling cluttered.

Can I fire my SB600 without using my D90 on-camera flash as a trigger (with CLS/TTL)?

Question

So as mentioned above, I have a D90 and an SB600. I can set up the SB600 to be used as a flash on-camera and off using TTL w/ the D90 as a commander. What I'm trying to understand is can I fire the SB600 without using my on-camera flash as a trigger? Maybe I don't quite understand how CLS/TTL works, but I was thinking that I'd be able to put the SB600 wherever I'd like and could fire it wirelessly (there's also an AA setting that i'm not sure about). I know that Pocket Wizards and Cactus wireless triggers exist and I think I understand how they work, but I'm wondering if they're a requirement when you're using all nikon gear with a body that is a commander...

Thanks.

Answer

You can absolutely use other triggering mechanisms, but the wireless part of the CLS uses the on-camera flash.

One way that's cheaper than the PocketWizard route is a cable. Refer to Strobist's Lighting 101 Series for hints on connectivity options.

If you're using Commander mode, did you set the on-camera flash to -- (essentially off)? From what I can tell, by shooting a picture of my camera and my SB-800 into a mirror, the on-camera flash does appear a little bit, so you might see it catchlights (as I recently did), but does not contribute significantly to the lighting of the scene.

Can I achieve synthetic bokeh?

Question

In order to have a good separation of the subject from the background you usually use fast lens with high aperture and so on.

Can this, however, be achieved purely digitally?

Answer

Many options exist for creating bokeh digitally. Some purists will tell you that nothing exists like true bokeh created from large apertures. But, if you want to experiment many options are available.

  • onOne Software - Focal Point
  • Alien Skin's Bokeh
  • Photoshop has many plugins available as well

If you want to create it yourself in something like Photoshop or Gimp, you can using the Gaussian Blur filter effect. I will caution you though, this is a "pet-peeve" of many photographers, much like selective coloring. If you use this effect too much or too obviously to the viewer - it can have a negative effect on your image, so take caution.

Note, fast lenses with large apertures have other benefits besides the pleasing bokeh they produce. In my opinion the "synthetic" options do not match the real thing for bokeh either.

Why is the D7000 commander mode flash firing during exposure when the manual says it won't?

Question

I'm wondering if I'm using the D7000's Commander mode incorrectly. Page 225 of the Nikon D7000 manual says

The built-in flash does not fire [in "--" Option], although remote flash units do.

Yet what I've found is that the built-in flash in fact does fire, adding ugly on-camera, direct flash to my photos especially for short-distance subjects. I present Exhibit A below, where it is seen that both the remote SB900's and the on-camera's flash are captured, even in "--" Commander option. How do I fix this?

Exhibit A

Answer

They lie.

It does, it just not supposed to fire enough to matter. The flash is how it communicates with external units.

You can get an SG-31R unit to block it and let the IR only through.

Your other option is to ditch CLS and go with radio triggers - of which, if you search, we have various questions about.

What software tool can I use to convert a photo to line drawing?

Question

What's the best way to do this, using free software?

I want to convert photos to line-drawings, maybe cartoons ...

Answer

Do you want a bitmap image that looks like a drawing or do you want to vectorize the image?

To create a drawing effect, there are several filters for GIMP that will do that into some extent. Many simple photo manipulation programs have filters like that, too.

For vectorizing your image, you may want to try potrace.

Wednesday, October 26, 2011

How can I think logically about getting correct exposure with flash?

Question

I recently got a new off-camera flash (Nikon SB-700), and I'm having trouble thinking about the variables that go into proper exposure.

For example, without flash, I have a little mental decision tree that went something like this:

  • If shooting very long exposure then use manual mode with camera on tripod. Choose aperture to suit desired DOF and/or choose shutter speed to suit desired exposure time. Try to use ISO 640 or lower. Do not use exposure compensation (because in manual mode it's pointless).
  • Else if shooting fast moving subject, use shutter priority and ISO auto. Tweak exposure compensation to prevent blown highlights or blocked out shadows.
  • Else use aperture priority, and choose suitable DOF. Make sure that shutter speed is no slower than 1 / focal length. Compensate for slow shutter speeds by 1) Raising the ISO, or 2) Using a tripod, or 3) Bracing the camera or yourself against something. Tweak exposure compensation to prevent blown highlights or blocked out shadows.

For an amateur like me, the above algorithm covers just about everything I do. I could probably even make a flowchart out of it.

Now that I am trying to learn about flash photography, things are suddenly very, very complex, and I feel lost.

My question is: Is there a similar mental flowchart or algorithm that can I use as a guide for flash?

Answer

For me, the workflow with a single off-camera flash goes something like this:

  • Attach gel and/or modifier to flash according to ambient light and desired effect.
  • Place the flash where I want it to be - taking into account desired angle, whether I want the flash to be out of frame or behind something, reach, desired apparent size of light source (bigger near subject - gives softer light), desired light falloff (faster near subject).
  • Choose aperture and ISO so I would get desired DOF and background exposure level (often underexposed to add impact for the subject) with shutter time no faster than sync speed.
  • Turn on/enable the flash.
  • Am I in hurry? If yes, set flash to TTL exposure metering and camera to manual or aperture priority mode; if not, use both in manual mode.
  • Is the subject moving? If yes, decide if rear curtain sync should be used.
  • With manual flash: guesstimate or calculate approximate power level needed, set it.

    Formula for calculating needed power level:

    (distance ⁄ GN)² × (100 ⁄ ISO) × f-stop
    

    The distance should be metered between flash and subject in units used for guide number (could be either meters or feet).

    For example, at 35mm zoom your SB-700 has GN 31.5 on a DX body; with subject 3 meters away from flash, ISO 200 and aperture at f/2.8, you'll need power level

    (3 ⁄ 31.5)² × (100 ⁄ 200) × 2.8 ≈ 1/110 × 1/2 × 2.8 ≈ 1/79
    

    which is quite close to 1/64.

  • Take test shots and adjust flash position and power level/compensation to get desired exposure and effect (might skip this step with TTL in hurry).
  • Take the shot.

Why are there multiple contradictory ways to control flash ratio?

Question

I am reading the following introduction to flash photography:

http://www.cambridgeincolour.com/tutorials/camera-flash-2.htm

In this article, I came across two seemingly contradictory statements:

The "flash ratio" is an important way to describe the mix between ambient light and light from your flash. ...[T]he mix of flash and ambient light is adjusted using only two camera settings: (i) the length of the exposure and (ii) the flash intensity.

But the article also says:

The key to changing the flash ratio is using the right combination of flash exposure compensation (FEC) and ordinary exposure compensation (EC).

Don't these two statements say different things? Is the choice dictated by personal preference? Or do they mean the same thing?


EDIT: I just came across yet another suggestion to change the ISO instead (http://www.scribd.com/doc/60727727/42/If-You-Can%E2%80%99t-Find-the-Light-Create-the-Light):

See if you have a good blend. If the background is too dark, try moving up to the next level of ISO. Too bright a background? Lower the ISO.

This is really confusing for beginners like me!

Answer

They both say the same thing, though in a different order. You control the length of the exposure using ordinary exposure compensation (assuming you are in Aperture Priority mode), and you control the intensity of the flash using flash exposure compensation.

Essentially they have described the general terms in the first part, and the specific settings in the second.

Where could I find a detailed reference on all composition rules?

Question

I am looking for a good advanced reference about photographic/cinematographic composition rules. I have already checked this post:

Good books to learn photographic composition from?

but it doesn't look to be useful for me. What I am looking for is a book that describes in details the following rules: Rule of Thirds, Diagonal Dominance, Visual Balance, Depth of Field, and the like.

I already have a book about composition, Picture Composition for Film and Television, by Peter Ward, but it isn't very useful. For example, he defines the rules this way:

"The rule of thirds proposes that a useful starting point for any compositional grouping is to place the main subject of interest on any one of the four intersections made by two equally spaced horizontal and vertical lines."

Obviously, this definition is a simplified one, because the rule of thirds also propose, for example, that prominent lines in the image should be parallel to the horizontal/vertical lines.

Briefly, I want a book that contains every composition rule I can think of :-)

Any suggestions?

Answer

Have a look at "The Photographer's Eye". I found it superb and contains all the rules you can think of.

http://www.amazon.co.uk/Photographers-Eye-Composition-Design-Digital/dp/1905814046/ref=sr_1_1?s=books&ie=UTF8&qid=1292253318&sr=1-1

Which camera offers flexible remote control and good manual controls?

Question

I want to switch to a system camera, preferably one from the Micro Four Thirds or Four Thirds systems. Since I also want to do experimental technical setups like time lapse or astrophotography, I have a set of requirements that are not easy to check for on the manufacturer's websites.

Can you recommend a camera with

  • flexible remote control software (I'd like to have at least a live preview and controls for shutter, focus, f-stop, sensitivity and shutter speed)

    • Edit: Alternatively, a connector for an external monitor and a programmable remore control would also work for me. To put it another way, I don't need a computer in my setup, but I want the ability to control the camera without touching it.
  • the ability to provide a video stream like a webcam (ok, that's more of a bonus item, no hard requirement)

  • good manual controls (preferably two separate control wheels for f-stop and shutter speed)

  • low sensor noise

  • overall good usability

I suppose that adapters for M42, which is the standard connector on telescopes, are generally available. If I'm wrong, this becomes another "hard" requirement.

The cost of the body should not exceed $750, but in order to keep the answers relevant for everyone, please also list models costing more.

MTIA for all hints!

Answer

I would take a look at the Canon 60D. It is not a micro four thirds camera, it is an APS-C sensor sized camera. The reasons I suggest this include:

  • Larger sensors as opposed to the micro four thirds format should provide lower noise typically
  • The 60D has great manual controls, including an index finger wheel near the shutter release and a full size wheel on the back
  • Available remote control software(example1,2)
  • Not an extremely large body

It does not sound like you have a hard requirement for micro four thirds, only for cost, remote control software, noise performance, and usability. I think you will find all of this and more in the canon 60D for right around $750. The 50D would also be an option to save a bit of money.

Which is better - autofocus and recompose vs. manual focus?

Question

In some occasions autofocus doesn't focus what I intend it to. What is the better option - to use autofocus, focus what I want and recompose, or use manual focus in that situation?

Answer

In general, modern AF cameras have focusing screens optimized for bright viewing rather than accurate focusing. This means that the AF system is potentially more accurate than your eyes using the focusing screen, if the AF system is calibrated correctly.

I've found that the wider the lens is, the harder it is to achieve critical focus while focusing manually.

For critical manual focusing, either use Live view, if you have it, or install a custom focusing screen for your camera.

If you are using AF and recompose, I've found it useful to decouple the focusing action from the shutter release. Most cameras will let you assign focusing to a separate button, instead of having to maintain a half-press of the shutter while recomposing-

Image Stabilization in Lens vs Body: Which is Cheaper?

Question

Is Image Stabilization better in the lens or the body? Someone already asked that.

But I'm trying to make a purchasing decision. It seems that the short answer to my title question is that it's cheaper to put image stabilization in the body since you don't have to pay for it with each lens. But somehow that's not enough for me.

I guess I'm wondering how much cheaper it is. I would think it depends on what kind of equipment I purchase. I'm considering purchasing an entry level DSLR (Canon Rebel EOS T2i or ... preferably cheaper) I would probably stick with no more than two lenses. (I'm thinking one zoom lens and one "regular" lens.)

I'd love to price out two comparable sets of equipment, but I don't know enough about photography to really know if the lenses/cameras are of comparable quality. Can someone suggest a set of lenses cameras for this price comparison?

What brands put image stabilization in the camera?

Answer

You're right! This really depends on the specifics.

For some lenses, like the Pentax Limited series, but basically small prime lenses in general, a lens-based approach just wouldn't be possible at any price. I don't think Canon offers any prime lenses with IS at a focal length under 100mm, and Nikon's 85mm is their only exception to the same rule. Arguably, image stabilization is less important for wider lenses, but the fact remains: if you want image stabilization in a wide or normal prime — or even a short telephoto — in-body is the only way to pay for it.

So, if that appeals to you, in-body is very much the way to go.

If you're just looking to get the setup you describe — one zoom lens with IS and a prime, and you're done, and if you decide that you don't care about IS for the prime, there's really not much of a difference. Either way you're just buying IS one time, and there are some reasonably-priced entry-level zooms with the feature. Even if you buy two such lenses, the price difference due to other factors might be bigger.

If you're looking for a fast, pro telephoto zoom, the situation is different — but not uncomplicated, because we can't compare apples to apples. Canon's image stabilized pro 70-200mm f/2.8 lens is about $1000 more than the non-IS version, and the Nikon equivalents (there, the non-IS version is 80-200mm) have a comparable price spread. But, Sony's equivalent lens is in the ballpark of the pricier choices, and it's hard to tell if the couple-hundred in savings is due to IS or some other decision. And Pentax doesn't even make 70-200mm lens anymore, instead of focusing on the designed-for-APS-C 50-135mm. So is in-body IS a win here? Hard to say!

So, what I'd suggest is to take a look at How much do lens lineups vary across platforms? and the answers there, and think about what you expect your total lens system to look like, and think from there.

But — and I can't stress this enough! — you can't really plan until you get your camera and start shooting and discover what you like. When I decided on a camera brand, I sat down and made a chart of what lenses I would theoretically buy to cover this and that focal range, and plotted out my future purchases. Turns out, I love those tiny prime lenses I mentioned above, of which only one was on my imaginary roadmap. Now that's all I have! (Plus some older Pentax primes and a Lensbaby — also image stabilized.)

And, I value having those primes all stabilized. But if that weren't my thing, it might not be important at all. I have a friend who stretched his budget and immediately started out with the Canon pro-level 24-70mm and 70-200mm f/2.8 lenses (the later with VR), and he's been so happy actually taking photographs that he hasn't once stopped to stress about what other lenses to buy.

Tuesday, October 25, 2011

How can I manage my raw+jpeg files?

Question

I shoot in raw+jpeg mode. Mainly because I like to do post processing, but my wife doesn't wan't to be bothered with that. She likes to be able to take the photo and upload it to facebook without any other steps.

After a session out with the family, I can easily come home with 300+ photos. Most are good, but some are not even worth keeping. They may be blurry, over exposed, etc...

Right now I go through the files and delete any jpeg/raw combo that I don't want. Is there any (preferably free) software that will help manage them? It would be nice if it would link the two together so when I rename/delete/move one it does it with the other as well.

ps.
If you have any tips on how you manage your files, I am all ears.

Answer

If you are looking for a free option Picasa is probably your best bet. You can match it up with Gimp to do some more advanced editing. The preferred solution by many is Adobe Lightroom, which you can find on sale for around $130USD right now I believe.

Depending on the camera that you bought, you likely received a disc of software with it that may even include some pretty good digital asset management software of its own.

Resources

This question that has many answers might help you, although it does cover paid as well as free options: What software is focused on reviewing and organizing images?

A great group of articles can be found at this link: http://www.neocamera.com/article.php?id=dam-software It explains in more detail about how using digital asset management software can benefit the photographer, as well as going into detail about the paid options available.

A blog post at this very site may help you out as well, it specifically outlines the options available in Adobe Lightroom, but the same basic feature set exists in any digital asset management software such as Picasa or Apple Aperture. Here is the blog post: http://photo.blogoverflow.com/2011/10/lightroom-fundamentals/

What are good situations to use Canon Multi-Flash feature?

Question

What can be done with the MULTI-Flash feature of a 580ex II flash? What are good situations to use this feature?

Answer

Stroboscopic flash (Multi mode on Canon, Repeating Flash on Nikon) fires several flashes within short time, by using shutter time long enough you can capture them all. You can calculate needed shutter time (in seconds) by dividing number of flashes by frequency in Herz. For example, 10 flashes at 5 Hz takes 2 seconds to fire.

Typical application is single-frame chronophotography - capturing several phases of movement on same photo. So a suitable situation is where some interesting movement occurs. If the subject stays in one place during its movement (e.g. a dancer spinning), you can slowly pan your camera instead to have different phases recorded on different locations in your frame.

A variation of this is capturing the same subject from several angles on single frame by moving your camera around it while the flash is strobing. The subject is still, but the camera is moving. So a suitable situation is when there are several views of the same subject you want to show simultaneously.

For these techniques, dark background and light-colored subject tend to give better results.

Another case would be when you want to imitate multiple flashes with one flash and you need constant frequency to form a pattern - when your flash is moving at constant speed this will give you flashes at equal distances. If you don't need constant frequency, manually triggering the flash (e.g. with "Test" button) will give you more control over the outcome.

Best Android photo editing apps?

Question

What are the best photo editing applications for an Android camera phone such as the Nexus One, Droid, Droid Incredible, HTC Evo, etc...

Answer

I'd go with Photoshop Mobile app it seems the best that I've tried so far.

What will I be missing with Vivitar 285HV vs. LumoPro LP160 or Canon 580EX?

Question

I'm planning to get a hotshoe flash soon (I currently only have the onboard), and I have narrowed my choice down to several options, but I'm having a hard time deciding which way to go.

ETTL

This is probably the simpler option, and I think I would go ahead and buy the Canon Speedlite 580EX.

This would certainly work, but I have a limited budget, so I am considering a cheap (but decent quality) manual instead.

Manual

Mostly based on the lower cost, I am leaning towards these.

My Question

There are two parts to this... First, is there anything important I'm going to miss by going with a manual flash? From what I can tell it simply makes it easier to use it in auto settings.

Second, is there any significant difference between the LumoPro and the Vivitar? Both are inside my budget, but the price difference is significant, so I want to make sure there's not something I'm missing.

Answer

I just picked up a LumoPro LP160 (about a week ago, in fact). I'm pretty happy with it so far. As Matt indicated, this flash will be manual only, but it works fine as an optical slave (triggered by an onboard flash), and it works fine on the hot-shoe with TTL metering or in manual mode. If you end up getting remote flash triggers (ex: Pocket Wizard or Cactus), this should work fine with those, too.

I've seen reviews that show its flash power at maybe one stop lower than the Canon 580, which is pretty good for $160. Some of the reviews talk about its recycle time (it's slower than the 580), but I haven't had a big problem with that - especially if you use less than 100% power, it doesn't take long at all to recycle. All-in-all, I think it's a steal for the price.

Incidentally, you may also want to add the Sigma EF-530 DG Super to your evaluation list. It's a little more expensive than the LumoPro, but it also adds many of the Canon 580's features (E-TTL II, for example). Again, it's not quite the same as the Canon, but it's close, and it's about half the price. I went with the LumoPro figuring I'd get the benefit of the flash in manual mode for now, and if I decide later that I really need a 580, I can still use the LumoPro as a slave.

Monday, October 24, 2011

Is there an EXIF standard for tagging people in photographs?

Question

There are a number of websites that let you tag people in photos, such as Facebook and now flickr, but is there an EXIF standard for tagging who is in a photo, and where they are?

Answer

There is not. IPTC, another image metadata standard, also does not contain a "People" field. There's a Contact field, but that is used for contact information for the photographer.

Most people I know will store people as keywords. The main debate is whether or not to include spaces (would a photo of me be tagged as aaronhockley or as "aaron hockley"?). I don't use spaces since that simplifies things at times, but it's pretty subjective. I think the main thing is consistency... pick one method and stick to it.

What equipment and resources would help an aspiring strobist?

Question

I have a Nikon D700 and an SB-900, and I'm interested in getting started with off-camera flash for portraits.

I've skimmed strobist, but I'm looking for some really simple instructions for how to get started.

What equipment do I need to buy to trigger flashes? (Should I use Nikon's CLS or Pocketwizards, or just a sync cable)

What other resources should I look at to figure out how to get started?

Answer

For practice you can use the Nikon Wireless CLS. The D700 buildin flash can act as commander, and the SB-900 as TTL slave.
Pro: you can use full TTL capabilities. Con: range is limited, especially in bright areas. Range can be extended by buying a TTL-Flash-Controller (SB-12?).

Cable is a great start, too: it works very reliable, you can use full TTL, but of course range is limited to cable length.

Simple wireless triggers (like YongNuo RF-602, Cactus V4, Skyports, Radiopopper JRx) are the strobist way, cheap, quite reliable, range is good. Downside: no TTL, instead you need to make all settings on the flash itself.

Pro Wireless triggers (Radiopopper PX, Pocketwizard TTL) will give you full TTL with great reliability and good range, but for a hefty price.

I'd buy a cheap set of radio triggers like the YongNuo RF-602 for learning strobist, and see if this works for you. Of course you need to learn lighting manually for this, but I think this is a good skill to have, even if you are using TTL.

For resources of course have a look at strobist 101 and 102 at www.strobist.com.

How can I fix a “Cannot communicate with battery” error on Canon 7D?

Question

If I see the "cannot communicate with battery" error message on a Canon 7D, is there any way to fix it without sending it back to Canon?

Answer

A few things to try:

  • Try a second battery
  • Try a second body
  • Try OEM and third party batteries
  • Accept the warning message about the lack of communication and try to use the battery anyways
  • Try pulling the battery out and reseating it at least a few times
  • Try removing the tiny watch style battery as well as removing the regular battery at the same time. This will reset some if not all things on the camera, so keep that in mind.
  • Update your firmware to the newest version
  • Try a battery grip if you have one