camera copying of paintings

[olrob]

I have a number of watercolor paintings created by my wife. They are so large it takes 4-6 copies to scan them with my 8.5 X 11 scanner. Merging them and removing interfaces is a pain. I am trying to copy them using my digital camera on a tripod. It's an Olympus Camedia, 3.2 MP with 10X lens. I can place them far enough away and zoom in so the barrel, fisheye, etc. distortion of the image is a minimum. They are square within less than 1.0 degrees.
I have tried copying inside with regular lights and outside in indirect sunlight.
My problem is a subtle color caste on the images which is difficult to remove or compensate for. Since I want to end with a 7.5 X 10 inch print I feel the 3.2 MP grain is ok.
I am conversant with PSPX and Photoshop I can do many images fixes but I am not satisfied yet.

Any suggestions?
Could the outside light be a problem?
Since paintings are usually viewed inside a room with regular lights should I concentrate on that copy method rather than outside in sunlight?

Thanks

[tirediron]

Indeed the light is the issue. Ideally what you need is a camera with the ability to shoot RAW images (high-end P&S or DSLR) which will make adjusting this a snap, otherwise, it's going to be a matter of experimentation. Does your camera have a selectable white balance? Can it be further fine-tuned? That would, through trial & error, solve the issue. Try illuminating it with different types of bulbs and lights ,and use different diffusers (tissue, translucent plastic, etc).

[olrob]

I don't have the ability to shoot raw and don't want to have to buy another camera. I do have white balance capability but have never used it. Can you outline how it would work for my case?
I've heard of placing a grey card next to the painting and using that for color correction. How is that done?
I've also heard of placing a full spectrum color card as above. How would that work?
Some have said to copy inside with lights and others to copy outside in indirect sunlight. What are the pros & cons of each method?
Thanks

[willgoss]

I have copied a fair number of pictures (art work, lithographs) that I lighted using indirect florescent lighting......I found that the best rendition, one where the printed picture matched the framed picture, occurred where I used ISO 400, available light, White Balance on Auto and most important, Post Processing where I use Auto White Balance (or Levels Auto) depending on the graphics program....

It is interesting that when I tested with White Balance set to Tungsten or to Florescent, they looked different but were all similar after Post Processing......

The pictures included, oils, watercolor and older photographs.....

[ferret]

Go hire a camera for the day, at least 8mp

1.Cover the back of the canvas with a black cloth to reduce the light that gets to the back of the canvas (so the frame does not show up in the picture).

2. place the paintings on a stand outside with the sun light behind you.

3. put your camera on a try-pod and get it in the right position and as said above shoot in RAW.

We tried large format scanners and they just did not get the depth out of the images, this is why we turned to photography and kept with it.

This is the best way for copying large images, all of the images on www.Canvasart4U.com was done this was.

[Richard Kenward]

I have a number of watercolor paintings created by my wife. They are so large it takes 4-6 copies to scan them with my 8.5 X 11 scanner. Merging them and removing interfaces is a pain. I am trying to copy them using my digital camera on a tripod. It's an Olympus Camedia, 3.2 MP with 10X lens. I can place them far enough away and zoom in so the barrel, fisheye, etc. distortion of the image is a minimum. They are square within less than 1.0 degrees.
I have tried copying inside with regular lights and outside in indirect sunlight.
My problem is a subtle color caste on the images which is difficult to remove or compensate for. Since I want to end with a 7.5 X 10 inch print I feel the 3.2 MP grain is ok.
I am conversant with PSPX and Photoshop I can do many images fixes but I am not satisfied yet.

Any suggestions?
Could the outside light be a problem?
Since paintings are usually viewed inside a room with regular lights should I concentrate on that copy method rather than outside in sunlight?

Thanks

I've only just joined the forum and noticed this thread. My advise is from a position of a professional approach to the job, so what I have to say here may be of little interest<G> The successful coping of all flat artwork is a rather specialised task if it is to do full justice to the original, be it an old master oil painting, water colour or pencil drawing.

There are various problems to be overcome. The lighting must achieve a perfectly equal level of exposure from corner to corner and must be of the same colour! There must be no loss of information caused by even the smallest amount of glare. The camera must be set square to the subject for best results and focus must be perfect from corner to corner. Next the capture be it on film or digital capture must contain enough picture information at the highest possible real sharpness. Ideally you will be using what is known as a repro. lens with sufficiently wide a coverage for the job.

When we were shooting film we often used 10"x8" transparency film which we specially treated to keep contrast down to be able to retain detail at both ends of the brightness scale. These days we use a Betterlight scanning back (and special HID lighting) capable of achieving the full brightness range and at a quality far superior to 10" x 8" film. In just one capture it can hold 384MP of information which you will appreciate gives it a distinct advantage. BTW it is what many world famous art galleries and museums also use.

Having got your perfect capture it is necessary to adjust the file so that not only is the overall colour, density and brightness correct but also all the picture elements are too. This is an extremely difficult task for anyone not skilled and properly equipped. Finally you naturally need to be able to translate your digital files into a hard copy that is a true and correct copy of the original...not just a recognisable snap. This vital last part of the process is often one of the hardest aspects of the work, however unless every part is done to as near to perfection as is possible the end result will suffer.

I'm happy to try to answer all questions relating to the copying of artwork, however you may find it useful to first visit the web site of the specialised art studio I run <www.artisan-digital-services.co.uk>

Best wishes

Richard

[Colin Southern]

"I've heard of placing a grey card next to the painting and using that for color correction. How is that done?"

A gray card is - by design - "colour neutral", so when you photograph it under a light that has certain colour properties then the card assumes the properties of that light (ie photograph it under a red light and it will adopt a red colour cast).

So in photoshop - using the RAW converter - there is a thing called a white balance tool - to use it you simply click on the grey card and it will then adjust the entire image so that the red, green, and blue channels taken from the sample area on the gray card are even - thus it "nulls out" any colour cast.

Problem here is that if you want to adjust a jpeg file then you're going to need the CS3 version of photoshop, or above.

If you're keen, I'd be happy to adjust the images for you - we can use a free service called sendthisfile.com to transfer images of ANY size (even hundreds of MB) - so all you'd need to do is to send one image with a gray card present (or even a white piece of paper if you're desperate) and then any other images that were shot under the same lighting conditions. Offers there if it helps - no charge of course (it only take a few minutes to adjust WB and fix any distortion & levels issues + sharpen).

Cheers