Photographing art work

[zipart]

i have a 10d. i want to take digitals of my art work. sometimes when i do this the white of the paper looks gray. how do i prevent this? i am using the canon 28-135 usm lens. i don't have any special lighting equipment. sometimes i take photos outside mounting the paintings on a black piece of foam core. sometimes i take them inside with a flash. i have no special equipment other than the camera and two lenses and a tripod. is there a way of removing the gray with photo shop? i have that but no experience using it.
more and more national shows are accepting digitals of art work instead of slides for jurying. i need to learn how to take digitals of my art work which accurately represents it.

another question i have is making digitals into slides. i was told you could do this but have no idea how. the processing into sllides would be done at the camera store. has anyone done this? were the results satisfactory?

thanks in advance

zip

[acura nsx pilot]

Have you tried one of the custom white balance settings ? Are you using the flash on the camera or an external flash ?

[CyberPet]

You need an even lit surrounding to photograph your paintings (also avoid glare, etc). A good suggestion is to use a grey card (with a white area, grey area and a black area) to set the white balance, the white point and the black point, in your images.

The camera wants to "even things out" to a perfect 18% grey, so if the main part of your painting is white, then the camera will expose to even things out, you won't get that perfect white as in your painting. The grey card should help you in the post processing, so you can set the white point, etc (shooting in RAW should help).

The second question I have no clue about. Never heard about making slide film from digitals, sorry.

[robertwgross]

Have you tried one of the custom white balance settings ?

That has nothing at all to do with the whites appearing gray.

Actually, if you let the camera do things purely automatically, the metering attempts to make just about every white appear 18% gray. That is where the human must step in and do some exposure compensation. So for starters, when you let the camera meter a big white patch, crank in about +1 to +2 exposure compensation. When you let the camera meter a big black patch, then crank in about -1 to -2 exposure compensation.

For photographing a flat painting, for example, the conventional wisdom is to place the camera on a tripod shooting directly and squarely at the subject. Then use one flash at a 45 degree angle on the left, and another flash at 45 on the right. By adjusting the flashes correctly, you will get them to be even across the flat subject.

---Bob Gross---

[pdrow]

When I shoot for a local artist, I shoot without a flash. I put a white card in the first photo and shoot on RAW. I then use the eye dropper in the RAW converter and correct the color that way. We have been very successful with this method.
pam

[acura nsx pilot]

So by using a custom white balance setting in this situation it would have done nothing ?

[Headcase650]

A custone white ballance removes any chances of a color cast. If your whites appear purly gray, then it would have done nothing. Now if you grays have a warm (redish yellow} or a cool (blue) apearance to them then a custome white ballance would have been nessary.

[robertwgross]

If the true white subject shows up as gray, then that is likely to be an exposure issue, not a white balance issue.

On the other hand, if the true white subject shows up as pink or light blue or light green or something, then that is likely to be a white balance issue, and there are several different ways to beat that.

---Bob Gross---

[chtgrubbs]

Get yourself a Kodak Gray Card. Cut one of the larger cards in half. They are gray on one side and white on the other. Include both the grey side and the white in a non-image part of the photo so they can be cropped out. When your process your image use a levels adjustment layer. There are three eyedropper icons in the command box. Select the middle dropper, sample the white surface card and click OK. This will give you a neutral color balance. Look at your info palette and sample the white card and the gray card and all three colors should read out within a couple of units of each other. Now your white paper will probably still be gray and you adjust the contrast using the three sliders on the levels histogram display. Slide the left pointer to just before the left edge of the histogram. Now slilde the right pointer to the right edge of the histogram. Adjust the center pointer to get the best overall exposure. If you are looking for instrumental accuracy resample the white and gray cards. The white should measure about 240-250 and the gray should be about 120-130. Adjust histogram sliders to get the proper output. If your monitor is not calibrated I would suggest going with measured accuracy as opposed to visual. Sounds complicated but actually only takes a minute or so.

[robertwgross]

Some photographers carry around a small cardboard piece to photograph at the beginning of every shoot. At the top of the piece, there is a gray strip, white strip, or else a black-gray-white strip. At the bottom of the piece, there is a space to write in a session title, name, or location. The top part allows for better post-processing accuracy, assuming that you shoot RAW. The bottom part just allows for better record keeping.

---Bob Gross---

[CyberPet]

QPcard is one of those nifty things to have in the camera bag. I have the white/grey/black ones, but there's also colored ones and software to calibrate as well: http://www.qpcard.com/

[zipart]

thank you all for your advice. i use photography only to gather resource material for my paintings or take digitals for my web site (which is still underconstruction). i have never used a gray card. i have thought about investing in some lighting to take photos of my art work. when i need slides i take it to a professional but i would like to be able to take my own digitals. when entering national shows, the slides/digitals have to be perfect.
the only flash i have is the one that is on the camera. i had a flash for my canon elan but i found i rarely used it. i find flashes flatten subjects and distort values. would a flash be worth the investment for doing this kind of photography?
would your advice apply to photographing winter snow? i know the same thing happens then too.

zip

[robertwgross]

the only flash i have is the one that is on the camera. i had a flash for my canon elan but i found i rarely used it. i find flashes flatten subjects and distort values. would a flash be worth the investment for doing this kind of photography?


A single flash mounted on the hot shoe will get fairly poor results. Like you said, it flattens the subject. Of course, the subject is flat.

For this, you want two flash units, one to the left and one to the right. Connect via PC cables or else via Canon wireless flash system.


would your advice apply to photographing winter snow? i know the same thing happens then too.


For snow, the main thing to do is to use exposure compensation to make the whites look white. Just don't push it too far. Early morning light on a flat field of snow can be breathtaking.

---Bob Gross---

[tim]

This book (http://www.amazon.com/exec/obidos/tg/detail/-/0240802756/102-9127707-6895351?v=glance) has a whole section on photographing artworks. It also has a lot of other useful information, mainly basics of lighting difficult objects.

[chtgrubbs]

You need two lights of matching output in both light intensity and color quality. I prefer Lowell TotaLights or V-Lights. The design of the reflelctors gives them very flat even output. The halogen shop lights available at home centers are a viable alternative . Small strobes are also an alternative although you need a flashmeter or considerable experimentation to accurately determine exposure.