Are you asking if it is legal to print out photographs of someone else's oil paintings (it is not) or do you need advice on how to capture true colors and texture on photographs of your own artwork?

Hi Cecile,

its more of the later point, although the painting is not mine, but a friends.

Libhatti, if you want to photograph your friend's artwork indoors, I can explain general principles and details re: lighting, angles, off-camera flashes, umbrellas, flash transmitters, and so on -- but this guy does a pretty good job and his tutorial should suffice: Matt Greer. 

Given the weather, however, I strongly recommend going outdoors and taking advantage of the beautiful natural autumn light while you can. Hang the painting vertically on a flat wall, using a dark matte cloth in the background if you want. Choose a good lens, select a low ISO setting and an aperture between f/5.6 and f/11, and use a tripod if necessary. I suggest using a gray card for middle gray reference, just to make sure your white balance is properly set (NB: you may have to alter your setting manually). As noted in Greer's tutorial, you can also shoot RAW images, photograph the gray card in the natural light, and then use said gray card to set your white balance at the post-processing stage, but that would be more time consuming. If you follow the steps outlined above to photograph the artwork outdoors (in the early or mid-afternoon, if possible), you should be able to create images that will not require any photo editing software use.