Showing posts with label wide-angle. Show all posts
Showing posts with label wide-angle. Show all posts

Saturday, May 26, 2012

Looking for a reasonably priced wide angle lens [closed]

Question

I have a Canon Rebel XS and recently I've been looking for a wide angle lens. Specifically, anything less than 28mm. Do you guys have any recommendations for me?

I'm looking for something in the $400 range if possible but feel free to suggest others too.

Asked by codedude

Answer

Have a look at the 'Tokina AF 12-24mm f/4 AT-X Pro DX'; a new model would cost you about $600, but you should find a used older model for the price you quote.

Answered by Gillie Bengough

Friday, May 25, 2012

What advantages does the Brenizer method have over Photoshop blur?

Question

I have seen a lot of posts lately about the Brenizer method. It looks smashing, but at the same time, I am fairly certain I could recreate the look using blurred layers in Photoshop. Apart from having a high-resolution picture using Brenizer's technique, are there other advantages I'm missing from just taking one wide-angle shot and manipulating it in PS to mimic the look?

Answer

Most techniques that are 'properly' accomplished in-camera, but can also be approximated in software, are generally better in-camera. No software filter can replicate the quality of bokeh afforded by a good-quality lens (although Photoshop's Lens Blur filter does a decent job).

Having said that, the Brenizer method is relatively time consuming, both in the field and in the computer, and requires a fast lens, so whether or not you do it 'properly' or with straightforward blurring really depends on what you're doing with it. If you're just taking a family portrait shot, you may as well 'cheat'. If you're taking a shot for your portfolio or for a professional wedding shoot, it's worth going the whole hog.

Answered by ElendilTheTall

Thursday, May 24, 2012

Brenizer method vs Photoshop blur

Question

I have seen a lot of posts lately about the Brenizer method. It looks smashing, but at the same time, I am fairly certain I could recreate the look using blurred layers in Photoshop. Apart from having a high-resolution picture using Brenizer's technique, are there other advantages I'm missing from just taking one wide-angle shot and manipulating it in PS to mimic the look?

Answer

Most techniques that are 'properly' accomplished in-camera, but can also be approximated in software, are generally better in-camera. No software filter can replicate the quality of bokeh afforded by a good-quality lens (although Photoshop's Lens Blur filter does a decent job).

Having said that, the Brenizer method is relatively time consuming, both in the field and in the computer, and requires a fast lens, so whether or not you do it 'properly' or with straightforward blurring really depends on what you're doing with it. If you're just taking a family portrait shot, you may as well 'cheat'. If you're taking a shot for your portfolio or for a professional wedding shoot, it's worth going the whole hog.

Answered by ElendilTheTall

Friday, May 4, 2012

How do Cokin and Lee filter systems compare to each other?

Question

Is there any material difference between Cokin and Lee filter systems?

I'm looking for a limited range of filters - ND, Grad ND and Polariser - for use with a Sigma 10-20 Wide angle lens on a Nikon D200, predominantly for landscapes. Which way should I jump and will my choosing (say) a Cokin filter holder rather than a Lee one limit me to using Cokin filters?

Many thanks

Danny

Asked by Danny Edmunds

Answer

I had some Cokin filters earlier, and was thinking of getting some again, mostly ND and effect filters.

The difference between the systems is first of all in the size of the filters. The Lee standard system uses 100 mm filters, while the Cokin P system uses 84 mm filters. The less common Cokin Z-PRO system uses 100 mm filters, so they should be compatible with the Lee system. I have also seen mentioned Lee filters made compatible for the Cokin P system.

From what I have read, Lee filters are higher quality (durable and even in color), but also a lot more expensive. A cokin user had problems with the neutral density filters not being really neutral, however that shouldn't be a big problem if you are using a digital camera, as you can adjust the white balance to compensate for any differences.

For a 10-20 lens you should be careful what holder you get. There are special low-profile holders for wide angle lenses that you might need so that it's not visible in the image.

Answered by Guffa

Wednesday, May 2, 2012

Better 10-22mm lens for Canon

Question

The famous Canon 10-22mm lens is quite well-built. The image is sharp near the corners, and it has a fast auto-focus system.

But unfortunately, it's aperture is relatively narrow...

Would there be any very wide angle lens of comparable focal characteristics, that would have a significantly larger aperture, and that would be adaptable on Canon cameras ?

Asked by Skippy Fastol

Answer

Quality of the Tokina 11-16mm F/2.8 is amazing. There is one for Canon mount. You lose some on the long end but if you already have some that starts around 17mm it should be good. Otherwise maybe you look at prime lens but I have trouble finding wide and bright ones for cropped sensor. I looked too :)

Answered by Zak

Monday, April 30, 2012

What's the difference between a wide angle lens and a landscape lens?

Question

Question pretty much says it all. Seems like when I look around people are asking "what's the best wide angle lens for landscape?", but on sites like LensHero they categorize wide angle and landscape differently.

Asked by tenmiles

Answer

There is overlap between the two terms, as you'll see as you browse the lists of both at LensHero. Basically, they're two different directions from which to approach the problem of narrowing down lens choice, and the site offers both approaches.

A wide angle lens has a specific definition without much flexibility — it's any lens with a wide field of view, generally considered to start at around a focal length of 35mm on a traditional 35mm film camera. So that's pretty straightforward: if the lens matches that, it should be in the list.

On the other hand, any lens can be a landscape lens — even a narrow focal length telephoto lens. A landscape photograph is simply one which portrays natural scenery of an area, and a wide angle lens is the easiest way to capture a vista, but not the only one.

So, from that point of view, the landscape lens list could be every lens ever, but there are some characteristics which are useful to landscape photography which may not be present in all wide angle lenses, and which aren't necessarily important to all wide-angle photography. That helps narrow down the list in a useful way.

One aspect of this is good performance stopped-down for maximum depth of field. Most lenses fit this, but a lens for landscapes may offer even-more-constricted-than-normal choices — many lenses designed for APS-C DSLRs don't close down past f/16 because of the diffraction limit, but for landscapes, you may prioritize depth of field over overall sharpness.

The flipside of this aspect is that good wide-open performance isn't very important, and for that matter, the "speed" of a lens doesn't matter — if you're going to be shooting at f/11 or f/16 or beyond, it doesn't make a difference whether the lens is able to open to f/1.4 or f/2.8. Providing good image quality at these fast apertures requires heavy and expensive lens elements, so a lens designed with landscape photography in mind instead can be cheaper, smaller, and lighter with no disadvantage.

Another aspect is across-the-frame sharpness. If you're taking pictures of centered subjects, it's usually acceptable (or for portraits, maybe even desirable) for the corners of the frame to be softer. For a landscape, this can be problematic, particularly if you have noticeable foreground objects near the corner of the frame (a frequent choice, as a nearby tree or rock often makes for a nice composition).

Back to the LensHero site... I notice that for Pentax mount, the DA 14mm f/2.8 tops the list for wide angle, but the DA 15mm f/4 Limited gets that honor for landscape. This makes perfect sense given the characteristics above: the 15mm Limited isn't as fast, but when stopped down, it's sharper across the frame. And as a bonus, the 15mm is much smaller and lighter, which is a definite advantage if you're taking your landscape photograph from a mountaintop.

Answered by mattdm

Tuesday, April 24, 2012

What does “the telephoto end” and “the wide angle end” of a zoom lens mean?

Question

In the Canon Rebel T3i Manual, page 59, it's mentioned that "If you have a zoom lens, use the telephoto end to fill the frame with the subject from the waist up." Same note on page 61 and another one for landscape telling to use the "wide angle end".

I have EF-S 18-55 mm IS II lens which is a zoom lens. I've googled "telephoto end or wide-angle end", but all the results were lenses not an end. I don't know if I got it wrong but I thought that "end" would mean something that can be mounted on my zoom lens itself.

Asked by Akram Mellice

Answer

'End' in this case is just referring to the end of the zoom range available. So zooming in on an 18-55 lens would take you to the 55mm end of the zoom range, which would be the telephoto end, and the 18 mm end of the zoom range would be the wide angle 'end' (although on this lens the telephoto end isn't very telephoto). So while it may sound like a physical 'end' they're referring to, it's just the ends of the zoom range of the lens they are referring to

Answered by Dreamager

Monday, March 19, 2012

What to look for when testing a wide angle lens before buying?

Question

I'm looking at buying a used wide angle lens (specifically Canon EF-S 10-22mm f/3.5-4.5 ) for a crop camera. The question What should one look for when buying a used lens? covers the basics when buying a used lens.

I'd like to get tips about what to specifically look for when testing a wide angle lens. What are most likely to be flawed with a wide angle lens and how to test for these flaws. How to push the limits of the lens to make sure it's not one of the few with serious problems.

Keep in mind that the testing will happen in an uncontrolled environment, like a shop, public place or at the sellers house. This means that the test have to be quick and easy without using a rigid test setup.

Answer

It will be difficult under such circumstances to do anything but a cursory inspection. The best advice would be to know the lens you are going to buy and it's particular quirks.

Ideally, the seller could send you a picture taken with the actual lens in advance, so you could see for yourself, barring that, if you could bring a camera and a laptop, and try some tethered shooting, you could get a good idea of any issues pretty fast. If that's not practical, at least bring a lens and do some chimping.

Check for general condition and functionality. Specifically for wide angle, the obvious things to check for are corner sharpness, fringing, vignetting, and amount of distortion.

Obviously, any wide angle lens is going to go have all of those to some degree, which is why you have to know what to expect going in.

Answered by cadmium

Sunday, February 26, 2012

How can I shoot wide angle zone plate photography?

Question

I like the look that is possible with zone plate photography. I've google around a bit and it seems that pinhole and zone plate photography on a DSLR, especially a crop body DSLR, results in medium telephoto type shots. It also seems that the focal length is dependent upon the distance from the plate (or pinhole) to the sensor.

You could take a body cap and inset it some into the camera body, but it will eventually strike the mirror. Going one step further, I could use mirror lockup and and get the zone plate even closer to the sensor. If I do that, what sorts of problems am I likely to see. And this raises an interesting question, does the Canon 40D even have a mechanical shutter and would this inset device interfere with that?

Asked by Paul Cezanne

Answer

One option is to use a zone plate optic with a wide-angle converter lens in front. An off-the-shelf solution is Lensbaby's zone plate optic + wide angle 0.6× or super-wide angle 0.42× conversion kit. Since the optic gives a focal length of roughly 55mm, the results will be about 33mm or 23mm.

Examples are available on Lensbaby's site with the zone plate with super-wide converter and regular wide converter.

Answered by mattdm

Friday, February 24, 2012

What are my options for an FX wide-angle prime to suit the D800's successor?

Question

I have a D700 which I'm not planning to replace at this point in Nikon's product cycle. I'll porbably buy the D800's successor. Not because I don't like the D800 (especially its usability improvements around focus mode switching and Live View, which don't seem to have attracted much attention) but because I can't justify the cost when there are too few things the D800 does that the D700 doesn't.

Anyway, although I'm keeping the D700 for now, I'm planning to buy a wide-angle prime so that I end up with this in my bag: D700, SB-800, 105mm micro, 50mm, wide-angle.

I need to choose a wide-angle lens. The 14-24 is a great lens, but too big for me to routinely carry it. So I'm going to buy a wide-angle prime. However, I don't want to buy a prime now that turns out to be disappointing on the replacement body I eventually buy.

As for focal length, the 35mm is a lens I could like but it's too close to the 50mm for me to seriously consider buying it. Hence I'm looking at the 20mm - 28mm focal length range. Which Nikon primes have sufficient micro-contrast to work well with bodies with a finer pixel pitch at full frame (I'm going to assume for the sake of the discussion that that is what the D800 successor will be like: FX, high resolution)?

I'm going to assume that the 24mm f/1.4 is going to be among the suggestions, and in fact Nikon points it out in the technical guide for the D800 as being suitable for use with the D800E. It's heavy and expensive so I worry that in practice I'd leave it behind with the 14-24. So I'm interested in my other likely options.

Budget is important for recommending the right choice. But I'm pretty flexible for a reason: new lenses will be launched between now and the launch of the D800's successor. So maybe the right approach is to buy something less expensive now and upgrade later to some not-yet-existing lens. The principle I'm going to operate on is that I'm OK with buying a lens now, that's actually not suitable for the D800's successor at up to €400. I'd just sell if that seems like the right thing to do, and not worry about losing some of its value on the re-sale. On the other hand, if I'm going to spend more than €500 I don't want to plan to replace the lens.

My planned uses are principally travel photography, interior shots, architecture, some environmental portraits.

What do you say?

Answer

My suggestion would be that you hold off on a wide prime if you're buying it for the future. Any of them are okay if you're looking to match them with the D700's sensor, but the D800 (and, one would assume, its successor models) has about the same pixel density on the sensor as the D7000, and the Nikkor full-frame wide angles are showing their age on that model (and not well, either). They're not particularly sharp at the corners, and display significant vignetting already -- and that doesn't account for performance at the edges of a full-frame sensor. If you can, try to get some feedback from people who've tried them on a D3X, but I wouldn't expect any rave reviews.

Since Nikon has decided to step into the miniature medium format world -- using a sensor that's verging on the very edge of even theoretically perfect lens performance -- and their stable of full-frame wide-angle primes is getting a little long in the tooth, I'd expect to see some newer design trickling in over the next few years. So buy for the short term rather than for the future if you're waiting for a successor to a model that isn't actually shipping yet -- something that might show its age on a D800 could be the best thing that ever happened to your D700. And get the focal length you need rather than worrying about which one is "best" -- the best lens is the one that lets you take the pictures you want to take, not the one with the best specs, build quality or handling.

Answered by Stan Rogers

Saturday, January 28, 2012

What settings should I use to photograph aurora borealis with a WIDE ANGLE F4 lens?

Question

I've tried my first night photography of the stars last week. Most articles I've seen were recommending a fast lens, fully opened, @ ISO 800 and about 20 - 30s exposure, etc. Unfortunately, my only "fast" lens is a 50mm f1.4 which was fine but not as wide as I would have liked.

There is a strong possibility of aurora borealis tonight and I would like to use my wide angle lens (Canon EF 17-40mm f/4.0 L USM) With maximum possible aperture of f4, what settings should I use to produce reasonably noise free photo. I would like to omit star trailing if possible.

I will be using Canon 60D

Answer

I could make an educated guess..

Consider this picture, its EXIF data says exposed for 5 sec @ f2.8 at ISO 1600, ignoring the focal length of 14mm. and considering that you said most articles recommend shooting @ ISO 800 using max aperture (in your case f4) you should set your exposure for 20 seconds.
@ISO 400, shutter speed needs to be 40sec
@ISO 200, shutter speed needs to be 80sec
@ISO 100, shutter speed needs to be 160 seconds
but longer shutter speed might cause star trails.
Then again you can set the ISO to 3200 to reduce the shutter speed to 5 seconds.

Assuming the brightness of the Aurora Borealis is the same as in this picture.

I also suggest turning on the custom fuction on the 60D for high ISO noise reduction and Long Exposure noise reduction.

Wednesday, January 11, 2012

Which lens to buy: 50mm f/1.8G or 10-20mm as first extra lens for travel to Japan?

Question

I have recently bought a Nikon D5100 with a 18-55mm and a 55-200mm lenses kit. Now I am planning a travel to Japan (next April) and I would like to buy a new lens in order to make some practice before leaving for the trip.

Some of my collegues suggest me for a Wideagle others for the 50mm. I would also be more oriented for the Nikon 50mm 1:1.8G since it can shot great photos with low light conditions and make also very good Portrait with blur background.

In Japan I would like to shot a lot of details on the streets and people, more that portraits however.

Is the 50mm a good lens for this kind of photos or would you suggest something else? I have seen the 50mm 1:1.8G is out of stock in many shops (Amazon, Pixmania, ...). I live in Switzerland, does anyone know other reliable web sites for photo lenses? Thanks.

Answer

If you want to take pictures of the buildings - go with your kit lenses (18-55) and don't worry ;) Grab polarizing filter and you will have good pictures when it will be sunny (do not forget to unmount it when it is cloudy). 18-55 is perfect for the traveling and taking pictures of the buildings. Use F/5.6 and more for details.

If you want to shoot in low light, then get small tripod. 50mm F/1.8 will not help also if it is really dark.

If you want to take portraits, then 50mm is the best thing you can have (or 70mm), but you will feel not comfortable if you want to take picture of bigger building, you will simply fail.

10-20 will give you freedom, but you will not enjoy it for portraits...

Kit lenses are added with your camera just because you will be able to determine what you need next, but it doesn't mean that they are always bad and you need to invest more and more to get better ones ;)

In switzerland you can use www.toppreise.ch page and see the prices there.

Hope that helped at least a bit...

Friday, December 23, 2011

Why does the cheap kit lens seem to be sharper than the expensive L wide-angle?

Question

So recently, I was just browsing through Canon's product lists and found the 17-40 f/4 L to be quite interesting, although I will not buy it anytime in the near future. Still, I decided to make some comparisons, just for fun:

EF 17-40 f/4 L USM vs EF-S 18-55 f/3.5-5.6 IS

These shots were, according to the website, done with the same camera, aperture and almost the same focal length. What struck me is that the L lens seems to be only a little bit sharper in the center, and, even worse, the kit lens seems to beat it in the corner areas!

How can this be? Is the test flawed? Anything I missed out?

Of course, the 17-40 needs to draw a bigger image circle in order to suit FF cameras, and the 18-55 is optimized for an APS-C sensor. But until now I assumed I could still expect clearly better image quality even on an APS-C camera?

Answer

"L" lenses aren't always necessarily sharper than their non-L cousins. In fact, some of them are very much softer, often as a consequence of being two or three stops faster than the cheaper lenses, but sometimes just because they're a decade or two older in design.

What you do get with "L" lenses is professional features and the build quality of a light armoured vehicle. For instance, you might not care so much about a constant aperture while zooming, but I can guarantee that somebody who is using separately-metered studio-type flashes either as main or auxiliary lights would. And the manual focus ring on kit lenses (so far true of both Canon and Nikon) is just a little less than useful.

There have been a couple of "L" lenses that were, frankly, lousy lenses by most objective standards, the most notorious being the now-discontinued 50mm f/1.0. Considering it as a "standard" lens and using it at f/5.6 or f/8, you'd have to be an idiot to spend the extra two grand on that lens (and that was in early-'90s dollars) -- but when TMax P3200 was that fastest thing around, being able to go to f/1.0 for "available darkness" shooting made the difference between being able to get the shot and not being able to get the shot. It didn't matter that the $50 (at the time) f/1.8 version could shoot rings around it at other apertures -- that stop and a half meant everything to the people who needed a lens that fast. Most of the "L" series for the old FD mount were like that -- they filled a niche that pros needed to do their jobs, but were actually worse for general photography than the non-"L" variety. Things got better for the AF EOS era, but there have been a couple of stinkers along the way too. The worst of them have already been replaced by updated designs, but some adequate performers are still in need of an update.

If you want (or need) the build quality, usability and environmental sealing of a pro lens, then the "L" is almost always worth the money. If you're making pictures for your own pleasure and can afford the sometimes fiddly and fragile nature of consumer lenses, then the newer, cheaper optics are often a much better option.

Tuesday, December 6, 2011

What normal lens would have better edge sharpness than Pentax SMC Takumar 28/3.5 on my Canon APS-C DSLR?

Question

I'm using Canon 450D + SMC Takumar 28/3.5 for nature shooting for a couple of years. And I'm not satisfied how it works. Now I have the option to buy something else and upgrade my wide-focus lens.

Could you please advise anything to get better results (colors, sharpness near edges; I do not like idea to do much work in Lightroom, just minor corrections)? Budget approximately 400 euros.

Please do not advise to get something from "L" series.

Answer

Another 28mm to check out is the Zeiss 28mm/2.8 Contax/Yashica mount lens. It's a very nice lens, and there are a large number of adapters available for it, some including focus confirmation chips. You can find quite a bit of information about this lens on the web, but here's review to get you started.

I just looked at the ebay.de and saw a couple very clean copies available for around 350€

Wednesday, November 30, 2011

Why do wide angle prime lenses have relatively small apertures?

Question

I've noticed that many of the wide angle prime lenses (at least for Canon) have somewhat smaller apertures than their normal or telephoto counterparts. E.g. the regular Canon 24mm prime is f/2.8 while the 50mm prime is f/1.8.

Theoretically, it should be possible to make large aperture wide angle lenses, as their opening will be much smaller than primes with longer focal lengths. So, why are there no wide angle lenses with larger apertures? Does a larger aperture place limits on the smallest aperture a lens can have, as this could have an impact on the depth of field for landscape photography.

Answer

Broadly speaking wide aperture lenses are easier to design the longer the focal length. The reason that you don't see any 400mm f/1.4 lenses is due to manufacturing difficulties, e.g. keeping dispersion low while producing elements of the size required for such apertures. It's worth restating that the designation f/1.4 means that the size of the aperture stop is the focal length divided by 1.4, which for a 400 f/1.4 is a whopping 285mm. Technically it's the image of the aperture stop that must be that size, which means the front element has to be at least that big.

If you look at the widest of Canon's superteles you see a pattern that 150mm seems to be about the limit of what is economical:

  • 400/2.8 = 142mm

  • 600/4.0 = 150mm

  • 800/5.6 = 142mm

Lenses with focal length less that the registration distance (about 46mm for most DSLRs) have to incorporate what's known as a retrofocal design, which is essentially a reverse telephoto group (or "wide converter") at the back of the lens. The wider the lens the more corrections have to be performed due to the retrofocal design, and these corrections are more difficult for wide apertures lenses.

You can see this if you look at the design of the Canon 24mm f/2.8 and 50mm f/1.8:

Canon 24mm f/2.8

50mm f/1.8

The reason 50mm offer such good price/performance ratio when it comes to aperture is that for 35mm cameras that 50mm sits at the sweet spot where the focal length is long enough to allow a simpler non retrofocal design, but not too long that large pieces of glass have to be used to give a good f/number.

Thursday, September 1, 2011

How can a 24-70mm and a 10-22mm both be "wide angle" lenses?

Question

I've been looking at a 10-22mm lens for my Canon T2i. I've also come across some other "wide angle" lenes, like the Sigma 24-70mm F2.8.

I don't understand how a wide angle lens can be such high numbers. The kit lens is 18-55mm, 18 is lower than 24, so does that mean the kit lens is a "wide angle lens?

Also, the 10-22mm lenses are pretty expensive. Around $400 - $800 (and up), depending on the aperture. Any tips for getting a low priced wide angle lens? I was thinking about the Rokinon FE14M (14mm prime) that amazon.com has for $289. Not the "best" lens but it seems to have OK ratings for the price and I thought I could trade up later. Any reasons that is not a good idea?

Answer

Traditionally, lenses wider than 24mm on full-frame are "ultra-wide". On a smaller-sensor Canon DSLR, a 15mm lens provides that same field of view (16mm on Nikon, Pentax, or Sony; 12mm on Olympus/Panasonic). So on an APS-C camera, a 20mm lens would be "wide" but not "ultra-wide" — but with the increased field of view of full frame, that would fall under ultra-wide.

On full frame, a 35mm lens is wide angle (but not ultra-wide); that same lens would be "normal" on an APS-C camera.

In either case, yes, the 18-55mm kit lens is a wide-angle lens. On a crop-factor DSLR, that nicely covers a reasonably wide angle, through normal, up to a moderate "portrait-length" telephoto.

(On some systems, some lenses designed for APS-C cameras won't work at all on full frame. Or, they'll work but with poor performance in the corners — and on Nikon, for example, this is compensated-for by automatically cropping-out the edges when a designed-for-APS-C lens is attached. But it's pretty much universal that full-frame lenses will work on APS-C.)

Tuesday, August 16, 2011

How to use wide-angle lenses on cloudy days?

Question

For this question, I am mainly interested in architecture photography, but it may concern other subjects.

When I go for a day or two to a city, I try to limit my weight and for this purpose I usually only take one lens with me. Sometimes I choose to take wide-angle lenses.

When I use wide-angles on cloudy days and try to take architecture photos, the result is dull, wih a lot of diffused light and little contrast. It is a pity, because where I live, the sky is actually very beautiful on cloudy days, with a lot of tones and shades, but the contrast with buildings makes that all this subtle shades of white/light grey are lost when trying to find a correct exposure for the scene.

I am looking for ways to overcome this issue or more generally for advices on what to do with wide-angle lenses on these cloudy days (like "just avoid to take the sky and concentrate on building close-ups")?

I try to avoid post-processing fixes as long as I can, just as a personal choice (but I still use basic post-processing like histogram equalization), so I would appreciate non-processing issues maybe a bit more, but all advices are welcome.

I use mainly prime lenses, and have no hood for them. I suppose it may help to limit the issue to use one but I suppose it won't completely fix it. Also this issue concerns digital cameras - film is great on cloudy days!

Answer

It sounds like the light metering in your camera is the prime source of problems on cloudy days. You should be able to take great pictures too in overcast weather. In fact, clouds will often bring the entire dynamic range of a composition down to a range where you stand a better chance to capture it all in a single photo, from the deep shadows to the brightest areas, and with more saturated colors to boot.

If your camera has multiple metering modes (spot, center weighted, average), then try to experiment with each of them to see the result. Also, if you are not already using the histogram functionality, learn to use that too in combination with exposure combination. The light metering modes in the camera will attempt to compensate for average situations, so in any given composition, you ultimately have to trust your own eyes and your own artistic direction. Use the exposure compensation dial or manual mode to adjust the decisions made by the light metering algorithm. Then you are completely in control of the image the camera captures.

Higher end cameras will have dedicated buttons or dials for quickly setting the exposure compensation, or for controlling both aperture and shutter speed in manual mode. On a lot of entry level dSLRs it is possible to program other buttons to serve as metering mode selectors and exposure compensation controls.

Monday, August 15, 2011

Why is the Nikon 35mm f/2D AF considered a Wide-Angle lens?

Question

What makes the Nikon 35mm f/2D AF Wide-Angle Lens lens be considered wide-angle as compared to the Nikon 35mm f/1.8G AF-S DX Lens which isn't advertised as wide-angle?

Answer

The term DX on the 35mm AF-S f/1.8 indicates the lens is designed for a crop sensor format. On crop sensor cameras, 35mm is not considered wide angle. They (DX lenses) don't produce an image circle large enough to cover a full frame camera. When used on some full frame cameras - they will crop the center out and you effectively still get the same view as a crop sensor camera.

The 35mm AF is not a crop sensor lens and will work on both crop sensor cameras and full frame cameras - although on a full frame camera it will have wider field of view than on a crop sensor camera. Because of this wider field of view, it is considered somewhat wide on a full frame camera.

On your D7000, they will both have the same field of view (not wide, more of the 'normal' range, around the same field of view as a 50mm lens when mounted on a full frame camera). Imagine two circles (two image cirlces projected by their respective lenses), one bigger than the other (the DX being the small circle), but the same size rectangle (your sensor) in the middle of each - just large enough to fit fully in the small circle. They're not magnifying the image more than each other (since they're the same focal length), so the rectangle in the middle is still representing the same portion of the image.

(Rough sketches)

enter image description here

On a full frame camera, leave the two circles the same, but now the rectangle (sensor) is bigger than the DX circle.

enter image description here

Wednesday, August 3, 2011

Why are wide-angle lenses so much more expensive?

Question

What is it about wide-angle lenses that makes them so much more expensive than an equivalent-quality tele or prime lens? Take the Canon EF-S 10-22mm USM, for example. RRP is nearly £1,000!

Are they very much more difficult/expensive to make? I'd dearly love to get into wide-angle photography, so how can I get the shots I want without having to pay such a large amount of money?

Answer

Firstly I wouldn't let the recommended retail price dissuade you — the 10-22 can be snapped up for £570 online. To answer the second part of your question:

how can I get the shots I want without having to pay such a large amount of money?

I would look at the non-Canon brand wideangles, such as the Tamron 10-22 f/3.4-4.5 for £337 or the Sigma 10-20 f/3.5 for £372. Also consider the used market - wideangle photography doesn't have to be as expensive as you think!

But yes, in general wide angle lenses are expensive.

This is partially due to the design, and expectations placed on the lens. Any lens with a focal length shorter than the flange-focal distance (the distance from the back of the lens to the sensor, also called the registration distance, I think it's 42mm on a Canon) has to employ a retrofocal design, which basically means it's a normal lens with a reverse telephoto stuck on the back. The extra elements required adds to the cost and makes the lens more difficult to design and manufacture.

Compare the design of the EF 14mm f/2.8 (top) to the EF 50mm f/1.8 (middle) and EF 100mm f/2.0 (bottom)

EF 14 f/2.8

EF 50mm f/1.8

EF 100mm f/2.0

images copyright Canon inc.

The 14mm is by far the most complicated, and you can clearly see the retrofocal elements at the rear. The 50mm is a simple symmetric design with only 6 elements. For completeness I've added the 100mm, as it's a telephoto design which allows the lens assembly to be shorter than the focal length (it's only 73mm long) for mainly practical reasons/cost. The reversed telephoto section of the 14mm does the opposite and makes the lens longer than it's focal length which makes room for the mirror in an SLR see this question for more on telephotos: Is there construction-agnostic term for a lens with a long focal length?

The other part of the problem stems from what you're asking the lens to do — bend light from a huge number of different angles and focus it on a single rectangular plane. Any lens at the edge of the performance envelope, be it wide, long, aperture will be expensive. As different wavelengths of light bend at different rates you have to work very hard to avoid chromatic aberration where the constituent colours of light split up and fail to align on the sensor. Combating this requires aspherical elements (coloured green in the 14mm diagram above. It's easy to grind glass into a sphere (simply spin it in front of a polisher) but to grind parabolic and other aspherical profiles is much harder (and therefore expensive). Wide angle designs also employs ultra-low dispersion glass for sharpness and contrast.

Telephotos can be just as expensive, but for different reasons. Light doesn't have to bend as far, so the design is simpler but this time the pure size of the glass elements required for a decent aperture (remember that f/2.8 means the [apparent] size of the aperture must be about one third of the focal length, which becomes really quite large once you go past 200mm or so) makes the elements expensive to produce (at this size dispersion & scattering is a big problem so UD glass and fluorite have to be used) and creates engineering difficulties in moving them around (motors and lens barrels have to be larger and stronger).

50mm is the sweet spot of lens design for 35mm SLRs, wide enough that the size of the elements required to maintain a wide aperture are still relatively small, but not so wide a retrofocal design is needed. This is why 50mm primes are such good value.

Wednesday, July 20, 2011

As a Canon DSLR user hoping to move to full frame do I have any wide angle lens options other than the Sigma EF 12-24?

Question

I'm a 550D user looking for a wide angle lens but eventually hoping to move to a full frame camera, in doing this I'm trying to avoid buying EF-S mount lenses due to the prohibitive cost of replacing them. This rules out Canon's EF-S 10-22mm as well as several Tamron, Sigma and Tokina lenses.

Do I have any other options?

Answer

When is this "eventually" going to happen? If not in the near future (it never is...), than I think you should positively consider the EF-S10-22mm. It is an amazing lens and when time to upgrade comes, you can resell it with a relatively limited loss. Think about bundling it with the Rebel upon sale.