Wednesday, April 25, 2012

What are the downsides to framing without glass over the print?

Question

I hate seeing the reflections of bright lights on my framed prints. (Actually, anybody's prints!) I'm about to frame this season's work for the gallery and I'm considering leaving off the glass. I can hold a matted print in my hand and say wow, but once I put the glass on it, I also see the reflections of the room lights or windows.

It is obvious that the glass protects the print, but from what? I have oil paintings (but not watercolors) hanging in my house that are not covered with glass. Is a photo more fragile than a painting?

I don't print giclee, so I'm not worried about ink running. Shoot, I don't even know if that is a problem with giclee.

One obvious solution is to use the special anti-reflective glass, like Tru-Vue, but that will increase the cost of my prints in an already down economy.

What issues am I facing? What other solutions are available?

Asked by Paul Cezanne

Answer

Oil paintings (and acrylics on canvas) are normally varnished for protection, and require periodic cleaning. (Traditionally, oils were varnished with Damar varnish, but over the past few decades a non-yellowing synthetic such as Liquitex Soluvar has become the standard; such varnishes can be removed with solvents that have little or no effect on the underlying painting. Synthetics are also available in matte formulations that don't have the problems of matte natural varnishes—they get their matte effect from waxes.) The cleaning process itself usually involves water in one way or another, which can be a problem for any water-soluble inks, dyes or grounds (such as, say, gelatine in a traditional photo emulsion).

Room air isn't just a collection of gasses; there are normally any number of aerosols (liquids and particles) suspended in it. If the picture is hung in a house, it's hung in a place where minute traces of every cooked meal are wandering around the place looking for a nice spot for a nap. There's vehicle exhaust, etc., wandering in off of the street. Dust abounds. Anything you've sprayed to clean or polish something else (including yourself) has overspray. There might not be anything that's visible or even particularly appreciable at any given moment, but over the years it all adds up. Eventually, your pictures will be covered in a film of schmutz that detracts from their appearance. So, by the way, will the matte.

Then there's the whole moisture moderation thing to consider. When pictures are framed properly, they form a package that significantly damps out fluctuations in the humidity of the surrounding air. Expansion and contraction (in absolute terms) depend, of course, on the size of the picture—a 20x30 inch picture on a natural paper ground will be a couple of millimeters larger overall at 90% humidity than it will be at, say 40%, while a 4x6 won't seem to change much at all. But the front of the picture is open to the environment without glass, while the back is protected by the mounting board. Even a small unglazed watercolor will begin to wrinkle visibly if it's not in a humidity-controlled environment. Depending on the ground (some papers are coated on both sides with a synthetic material that acts as a moisture barrier) you might see the same thing happening with your prints.

You can try alternatives, like varnishing or lamination, both of which can be had in less-glossy formulations (although I have to warn you that lamination tends to decrease the perceived "art value" among patrons). Neither, though, is a conservationally sound practice since they are irreversible. Whether or not that matters depends on the expectations of your patrons; are they buying pretty pictures with a limited decoration life, or are they buying heirloom works of art?

To sum up: there are good reason for framing works of art on paper behind glass. There are alternatives, but those alternatives also have their drawbacks. Your market; you decide.

Answered by Stan Rogers

Open standards in digital photography

Question

I'm interested which digital camera models and brands are most open standard friendly. I'm more an open source fan than a photographer, so I can be picky about openness and tolerant with performance and image quality. I suppose there won't be analogy of OLPC computer in digital camera world, but there shall be some models that meet more open standards than others.

Here is a list of standards I know about (I'm not 100% sure about this, feel free to correct me):

  • ¼" tripod mount is free to implement
  • 4/3 lens mount is more open than others, like Canon or Nikon mounts. It's not fully open, but at least interested third party lens manufacturers don't have to reverse-engineer camera electronics.
  • SDHC is more or less open
  • AA batteries are a standard factor compared to proprietary Li-ion batteries
  • Adobe DNG open raw format is supported by some cameras from Pentax and other manufacturers

So, any other recommendations?

Asked by user713303

Answer

There are literally thousands of "standards" used in digital photography, but few address what you seem to be asking: open standard hardware, os/file systems, etc. ASA/ISO film speed is a standard, as are APS-C and 35mm sensor sizes.

Sadly, all of the consumer oriented brands (Nikon, Canon, Sony, Olympus, etc.) are totally locked into a philosophy of locking you into their "system" with their hardware, software in the camera, software to decode the RAW files, etc.

And, IMHO, much of their proprietary software is second rate.

I have no hope for the DSLR business, perhaps cell phone cameras can take over P+S

Answered by Pat Farrell

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

Softbox selection for my hobby room

Question

My hobby room is a fairly standard room size, say 3x3M. The lighting isn't that great which doesn't help when I take photo's or record videos of projects etc.

I have a softbox that I use for 'product' type shots, but most of my pics are taken on the workbench, ie, during construction. Ok, so that's the situation. I am looking at lighting solutions and have stumbled onto this product:

http://www.ebay.com.au/itm/Photography-Photo-Studio-Softbox-Continuous-Video-Light-Lighting-Kit-VL-9026S3-/120804403445?pt=AU_Cameras_Photographic_Accessories&hash=item1c2080e8f5

This kit appears far more high power than other 'budget' kits (less than $300). I am sceptical about the light thrown though. My hobby bench is about 1.8x1.1M and I'd like to know (without going into to much detail) will these lights throw 'enough light' to scrub the shadows from my workarea for photos and videos? I am a little worried they will only be suitable for portrait type stuff.. Please rid my fears.

Bonus question - what max distance do you think these lights could adequately light a subject?

Asked by Graham

Answer

Reading the details of the eBay auction, you're right, it's not quite what they claim.

  • 7650 watts / 15 bulbs = 510 watts/bulb.
  • Each softbox takes five bulbs, and two softboxes are included (or three, depending upon what part of the description you read). That will therefore supposedly output 5100 watts, and give you five extra bulbs.

They are supplying 85 watt fluorescents, which are supposedly equal to 510 watt traditional bulbs. Based on a little searching, I'd say an 85 watt fluorescent bulb is probably more like 375 watts from a traditional bulb. The best way to judge light output would be to know lumens or a guide number, but they don't supply those. Also, note the size of those bulbs. They are not your standard compact fluorescent -- they're much bigger at about 4.5 in diameter and 9 in long. So, five of those means this is a big package.

For photo-only work, I would avoid getting a continuous lighting system because of price, size, and heat. But since you mention video, continuous lighting is necessary. Is it worth it? I think this all looks like low quality gear, and a cheap light stand would drive me nuts because it's likely to move too easily... but it may well be worth it, yes.

Answered by Dan Wolfgang

Monday, April 23, 2012

Why doesn't it make sense to compare an entry-level DSLR with a super zoom?

Question

A friend of mine told me that it does not make any sense to compare a entry level DSLR (e.g. Nikon D5100) to a super zoom (e.g. Nikon Coolpix P510).

So, what does he mean by "it does not make any sense"?

Asked by Jack

Answer

Comparing feature-by-feature is meaningless, a DLSR (even entry level) and a superzoom point and shoot are systems that choose almost opposite tradeoffs at every important design decision.

It's a bit like comparing a sports car and a mini van - while both are cars they are different systems designed for different purposes.

If the words small, light or cheap are high in your priority list you have no reason to look at DSLRs.

On the other hand, if you want to control how your photo looks no P&S in a the world will give you the power and flexibility of a DSLR (especially after you add another lens or two and an external flash).

Answered by Nir

How does photography for digital display only differ?

Question

I only want to capture images with the intent of displaying them on a digital screen. I do not want to print the images, ever. Do any specific considerations need to be made upon capturing the image or during post processing beyond these three things:

  • Screen color calibration/profiling
  • Sharpening
  • Resolution and display pixel density

I bring up this question because I feel like film photographers are more keen at producing work for their intended output format, and I would like to know what a strictly digital based workflow would require.

Asked by dpollitt

Answer

Additive vs Subtractive Color Space

One thing to think about is that an additive color space (RGB) is different from a subtractive color space (CMYK or others). There are colors you can display that you cannot print, and there are colors that you can print that you cannot display.

enter image description here

Notice how some yellows will print, but are not displayable, yet some greens are displayable, but not printable.

Blacks

Black is another really good example of a color that prints very differently that it displays, and displays differently depending on what device it displays on. Black on a CRT is the absence of light. Black on a cheap LCD is just very dark. (This is because an LCD is backlit and the back lighting is always on. Even when the cells are turned opaque some light leaks through.) You would think that this would mean a CRT would better contrast but in practice LCDs can get much brighter than CRTs.

Glow

Another aspect of displayed images is that they are luminous. A printed image needs room lighting reflecting off of it to be viewed. (And of course the color of the room lighting matters!) Consider the same image printed on paper and printed on transparency, a slide. Now illuminate the back of the slide. I suspect the slide will appear more vivid, since the brighter areas will glow.

This is a perceptual change, one that you probably can't account for while shooting, but I don't know. For example, I know this photo of mine has far greater impact displayed rather than printed:

enter image description here

Non-Traditional Inks

Another area is that printed images can have non-traditional inks, say a varnish or a foil. This would be exceptional difficult to capture on a display. (This is also getting way out of the realm of photography and into commercial printing, but it is worth noting in such an interesting question!)

Aspect Ratio

If you sell you work matted and framed it is prudent to restrict yourself to a small number of aspect ratios and sizes. This avoids an annoying, and expensive, inventory control problem. For example, I only sell 11x14, 10x20, and 12x12 images. (And I'm phasing out 12x12!) This restriction sometimes impacts your artistically. Your subject might not fit into either ratio but you are essentially forced to move to one of those ratios. This also changes the way you shoot. I constantly frame the shot and then widen it some, which is a challenge since I almost also shoot wide angle, say in the 20mm range on a crop body, and widening it sometimes isn't possible. I do this so there is some extra image in case I need to crop it just so.

This is not the case with displayed images. You are free to crop each image exactly like your vision tells you to crop it, which means you are free to shoot it exactly like you want to shoot it. However, almost all displays are landscape, not portrait, and if you are shooting for a display you'll probably find yourself avoiding portrait shots.

Future Proofing

From a future proofing standpoint I think you would need to say the image and the post-processing steps in a non-destructive and open format so that future display technologies could re-render your image. That's pretty pie-in-the-sky thinking though.

One thing you can do is shoot in Adobe RGB, not sRGB, just so you have a wider color space.

Answered by Paul Cezanne

Where are in camera ratings on the Canon 5D MkIII stored?

Question

The Canon 5D MkIII introduced a new featured that lets you rate images by using a dedicated rear button. I am interested in finding out where in the EXIF data that this rating is stored. I wasn't aware of any metadata field that ratings were typically stored in, so I'm not sure what they would be using.

You can read about the feature on page 255 of the manual. The manual notes that:

With Windows Vista and Windows 7, you can see each files rating as part of the file information display or in the provided image viewer.

Asked by dpollitt

Answer

Sadly I don't have a 5DmkIII but I've managed to figure it out with a bit of detective work.

The answer is that it's stored in an XMP header as the <xmp:Rating> value.

I started by hunting down a Canon 5DmkIII group on Flickr and found this thread. Click on one of those photos then go to the metadata page and you'll see one of the values listed is Rating (in this case with a value of 3). I'm certain that value hasn't come from post-processing because the metadata also shows it was processed in Lightroom 4. I use a 5DmkII and Lightroom 4, and rate all my photos before uploading to Flickr, and yet my photos don't have a Rating value on their metadata page.

Unfortunately all the photos I checked in that group have download disabled, so I headed over to dpreview.com's gallery of 5DmkIII test shots where I found this test image:

If you click that to go through to dpreview.com you'll see one of the tags on the photo is pre-production. Seeing that, and knowing dpreview.com's usual approach, it's pretty certain this image is straight out of camera.

So, I got the URL of the original image and posted it into Jeffrey's Exif Viewer. And there it is, right in the XMP section:

<?xpacket begin='' id='W5M0MpCehiHzreSzNTczkc9d'?>
<x:xmpmeta xmlns:x="adobe:ns:meta/">
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<rdf:Description rdf:about="" xmlns:xmp="http://ns.adobe.com/xap/1.0/">
<xmp:Rating>0</xmp:Rating>
</rdf:Description>
</rdf:RDF>
</x:xmpmeta> 
<?xpacket end='w'?>

Also note there's no Software value in the metadata anywhere: a further indication that this is straight from camera.

Finally, just to be absolutely sure, I took a straight-from-camera JPEG from my 5DmkII and ran that past Jeffrey's Exif Viewer. Sure enough, no rating value.

Answered by Mark Whitaker