The artworks shown at the exhibitions are often protected by a glass; sometimes that is a costly acrylic glass treated with a special anti-glare layer which makes it perfectly transparent, but most of the times it's a simple glass where you can almost reflect yourself and that it makes the camera take impossible. Sometimes the glass is demanded by the artists themselves right to prevent the occasional reproduction.
If you don't want to dismantle the frame from the artwork, it's possible to follow these expedients, with which you could obtain an acceptable picture. Do not use flash
- Photographing a glass with the flash, you get a flare that completely obliterates the underlaying subject. The flash is to be avoided even if the glass is not present, either for the glare and to respect the artworks which are sensible to the ultraviolet rays emitted by the flash; for this reason the flash is forbidden at almost any exhibition. Polarizing filter
- For the few who don't know it, the polarizer is a filter to be applied in front of the lens and that can be rotated. It permits the light rays to pass only if they have a determined angle; in practice, rotating it, we can choose which part of the light in the scene we want to get into the lens, thus culling other undesired light components, such as the glares over glasses, water and gloss surfaces, but even through the sky, making it in many cases more blue.
The polarizing filter may not completely get rid of all the glares in every part of the glass, except in optimal conditions, but we can even take more photos varying the polarization in order to recompose a picture from the usable parts.
The polarizers are of two kinds: linear (as to say normal, or classic) and circular. The circular one is necessary for the autofocus cameras and it's more costly. The results are almost comparable, even if often it's easier to find linear cheap polarizers extremely effective. Perspective correction
- If some strong glares on the glass can't be culled by the polarizing filter, it's possible to avoid them simply taking the photograph from an angle from where you don't see them, even if the artwork will come out distorted. It will then suffice to correct the perspective of the picture with a photo-retouching program (or with specific functions integrated in certain professional digicameras). The glares of lights on the ceiling are often easily avoidable raising the camera a little. Be folding screen
- This as last resort: if you don't have a polarizer nor the chance to correct the perspective, then have the cunning to go take photographs at the exhibits wearing black clothes, or white, or coloured as the rooms' walls. Placing yourself in front of the artwork so that the body reflects on the glass, we will act as a screen for all the light sources that could reflect onto. That applies to small sized artworks or if you have an massive circumference. The most zealots will carry a true study folding screen and the tripod, others will go around wearing the batman's mantle: people will think that your are playing a performance.