Help with photographing fine art

[buttershug]

My mother is a wonderful oil painter. She asked me to photograph her paintings ... I gave it a try (see my technique below), but am looking for pointers from those of you with more experience. Thanks, in advance, for your help.

What I did
~ Created a homemade light box (instructions i used)
~ Got rid of all other light sources in the room
~ Created a reference card using black, white, and gray construction paper
~ Set the paintings inside the light box
~ Used a tripod and put my camera (rebel xsi) in manual and used my 50mm f/1.8 lens
~ Set ISO to 100 and left it there (thinking I want as little grain as possible)
~ Played around with focal lengths between f/9 and f/26 (seemed to be a sweet spot for these photos) (thinking that a smaller aperture would create a sharper image)
~ Set the shutter speed so that the camera told me that the exposure would be right or just under-exposed
~ Photographed each painting so that it filled the frame as much as possible but always included the reference card and used a 2-second timer so that my pushing the button wouldn't cause camera shake
~ In post-processing (PSE8) adjusted levels using the white, black, and gray eyedropper thing on the reference card and cropped the photo using the set dimensions of the original painting

Whew. So that's what I did. Right? Wrong? What could I do better?
I'm honestly looking to learn so lay it on me.

[OsmosisStudios]

Originally Posted by buttershug

~ Played around with focal lengths between f/9 and f/26 (seemed to be a sweet spot for these photos) (thinking that a smaller aperture would create a sharper image)

You set the APERTURE, not the focal length. That doesnt change on a prime.

Those are some pretty small apertures. I wouldnt go any lower than f/8.

Was the painting perfectly perpendicular to the floor? Same with the image plane of the camera?

[dave_lines]

I would be afraid that the halogen lamps would catch the paper on fire, To me the set up looks like it should work. I do a lot of painting photography too, but I use natural light, I try to use about f11 and use the timer on a tripod. DAve

[buttershug]

Originally Posted by OsmosisStudios

You set the APERTURE, not the focal length. That doesnt change on a prime.

Those are some pretty small apertures. I wouldnt go any lower than f/8.

Was the painting perfectly perpendicular to the floor? Same with the image plane of the camera?

Aperture not focal length - I stand corrected.

Not quite perpendicular - the paintings were ever so slightly at an angle so I tilted the camera on the tripod to compensate. I spent a significant amount of time aligning everything, however I certainly fell short of perfect. Any suggestions to correct for this?

[buttershug]

Originally Posted by dave_lines

I would be afraid that the halogen lamps would catch the paper on fire, To me the set up looks like it should work. I do a lot of painting photography too, but I use natural light, I try to use about f11 and use the timer on a tripod. DAve

Hi Dave - I shared your fear so kept the lights on as little as possible to compensate. They also were at least 18 inches away from the paper...

I'll give natural light a try too. Thanks for the suggestion. Can you let me know the specific conditions you use? (e.g. direct light, cloudy day, inside, outside in the shade, etc.) Also, per OsmosisStudio's question - how do you keep the painting perpendicular to the ground and the image plane of the camera? Any tips?

[buttershug]

An example:

[LeeR]

I worked my way through college in the campus print shop. We used a big press camera at the time for copying images to press plates and the set up was very much like what you are showing. I would agree that there are two keys here: 1) keeping the lighting perfectly balanced and 2) keeping the image plane and the film plane perfectly parallel. Your idea of placing a white/gray/black reference card in the image is also a great idea for making sure you have white balance set correctly.(The pros use a card that has a whole rainbow of colors to help them spot slight color shifts due to camera and processing idiosyncracies.)
In my opinion, you are doing things right and, without the benefit of seeing the actual image in real life, your image above certainly is a reflection of your attention to detail.
By the way, from the painting I see your mother has a flair for dramatic lighting. Did she pass that on to you?

[LeeR]

I worked my way through college in the campus print shop. We used a big press camera at the time for copying images to press plates and the set up was very much like what you are showing. I would agree that there are two keys here: 1) keeping the lighting perfectly balanced and 2) keeping the image plane and the film plane perfectly parallel. Your idea of placing a white/gray/black reference card in the image is also a great idea for making sure you have white balance set correctly.(The pros use a card that has a whole rainbow of colors to help them spot slight color shifts due to camera and processing idiosyncracies.)
In my opinion, you are doing things right and, without the benefit of seeing the actual image in real life, your image above certainly is a reflection of your attention to detail.
By the way, from the painting I see your mother has a flair for dramatic lighting. Did she pass that on to you?

[LeeR]

I worked my way through college in the campus print shop. We used a big press camera at the time for copying images to press plates and the set up was very much like what you are showing. I would agree that there are two keys here: 1) keeping the lighting perfectly balanced and 2) keeping the image plane and the film plane perfectly parallel. Your idea of placing a white/gray/black reference card in the image is also a great idea for making sure you have white balance set correctly.(The pros use a card that has a whole rainbow of colors to help them spot slight color shifts due to camera and processing idiosyncracies.)

In my opinion, you are doing things right and, without the benefit of seeing the actual image in real life, your image above certainly is a reflection of your attention to detail.

By the way, from the painting I see your mother has a flair for dramatic lighting. Did she pass that on to you?

[LeeR]

I worked my way through college in the campus print shop. We used a big press camera at the time for copying images to press plates and the set up was very much like what you are showing. I would agree that there are two keys here: 1) keeping the lighting perfectly balanced and 2) keeping the image plane and the film plane perfectly parallel. Your idea of placing a white/gray/black reference card in the image is also a great idea for making sure you have white balance set correctly.(The pros use a card that has a whole rainbow of colors to help them spot slight color shifts due to camera and processing idiosyncracies.)

In my opinion, you are doing things right and, without the benefit of seeing the actual image in real life, your image above certainly is a reflection of your attention to detail.

By the way, from the painting I see your mother has a flair for dramatic lighting. Did she pass that on to you?