The varnish and oil paints used on these paintings give the complete product a shiny glare when struck by light, resulting in irregular coloring on a photograph. Take pictures of the paintings outside in natural daylight, preferably on a cloudy day, to avoid the glare and shadows that arise from the reflection of the sun's light. Avoid using the flash in your camera when photographing an oil painting. The flash from the camera causes hot spots -- regions that are so brightly lit they almost appear white -- and incorrect coloring in the photograph because of the glare that the oil paints produce.
Clean your camera and the artwork and ensure you have the correct equipment before photographing oil paintings. Remove any smudges that are on the painting's frame and remove any dust on the glass casing with a soft cloth. An SLR camera is good for these types of photographs because it gives clearer representation of the painting. Accessories such as a tripod and a polarizing filter are useful in helping reduce the glare and stabilizing the picture.
Determine whether you want your shot to include the framing and which parts of the artwork you wish to focus on. Photographs for show entries, advertisements or print production do not require the frame in the picture and should focus more on the painting. If you want to highlight the details on the oil painting, use the zoom function on your camera. Make sure not to stand too close to the painting when using the zoom function, or else the photograph will appear to "bulge" at the sides.
Different camera angles produce different results, including refraction and reflection of the light. Position yourself at the side of the oil painting and make sure there are no shadows on it; a direct approach creates more chances of reflection of light. Try to capture various aspects of the image, such as a broad view of the art piece, distinct focal points on the paintings and specific details. To avoid blurs, do not stand too close or too far from the image; experiment with different distances for a variety of shots.