Photographing Artwork without Glare


Today’s Question: I have clients for whom I photograph their artwork. My usual method is to have the standard 45-degree orientation of two lights far enough away from the artwork to provide uniform illumination. Often, when the paints are shiny and have a texture, that shiny texture forms a reflected image of the light source, which are small white spots all over the image. However, if I scan such artwork on a normal desktop flatbed scanner, these white reflections disappear. I would like to know the secret of how they achieve that. Is it due to using polarizers in the light path, or is it due to some feature of the light/detector system in the scanner?

Tim’s Quick Answer: Flatbed scanners can still produce glare on scanned artwork, but in general do a relatively good job because the light source is well diffused. Diffusing and polarizing the light can help minimize the appearance of such visual artifacts when photographing or scanning artwork.

More Detail: Glare is caused, of course, when a light source is reflected at just the right angle to create a bright spot in an area of the object being photographed or scanned. With a perfectly flat print you might be photographing or scanning, of course, it is relatively easy to avoid glare by setting two lights pointing from a 45-degree angle on either side of the print.

With something like an oil painting that has a variable texture and relatively high reflectivity, it can be much more difficult to illuminate the object in a way that there will be no reflections at all.

The first thing I recommend is to make sure the light source is diffused. To begin with, you’ll want a diffuser of some sort (such as an umbrella or soft box) in front of the light, so that the light is scattered to minimize glare. You also want the light source as close to the subject as possible to soften the light further. I realize this may seem counterintuitive, but the further a light source is the more directional (and therefore not diffused) it will be. Keep in mind, of course, that if the light source is closer to the subject, you may need to reduce the strength of the light source.

With this approach you may still need to fine-tune the position of the lights to ensure the softest overall light and minimal glare. In most cases with a highly diffused light source you can create photos without any visible glare.

Another great option is to use polarizing material in front of the lights, and on your lens, so that you can effectively filter out the glare that could otherwise result, even with very careful setup of the lights. You can obtain linear polarizing material in sheets, similar to gels you might use to add color to a light source. You can then use a polarizing filter on the lens as well, so that you’re able to prevent glare altogether.