Note that this article originally appeared in the May 2016 issue of the shutterBUG.
Photographing glass can be an exciting, and sometimes frustrating, exercise. When light strikes a glass object three different things can happen: 1-light can be transmitted; 2-it can be reflected; and 3-it can bend (refraction). These three unique properties of light need to be considered when attempting to photograph a glass object.
There are two main techniques for photographing glass. The overall goal of either technique is to define the contours at the edges of a glass object. Each technique is defined by the way light is seen at the edge of the glass, either as black lines or as white lines.
Black Line Photography
In black-line photography, a light source is placed between the glass object and a light-coloured (or white) background. The light from the source is reflected off the background towards the back of the glass object. When the light passes through the glass object its intensity is reduced at the edges of the glass, resulting in dark (or black) lines around the edges. This technique is relatively easy to do, needing only basic lighting and equipment.
White Line Photography
White-line photography is a bit more challenging. In this case, a black background is placed behind (and underneath) the glass object. Two light sources, either diffused floodlights or soft boxes, are placed so that light strikes the glass object at obtuse angles. Using pieces of black cardboard, you can adjust the amount and angle of light falling on either side of the glass object. Most of the light will be transmitted through the glass, resulting in a black (or very dark) image. However, some of the light striking the edges of the glass will be reflected and refracted (bent), resulting in white lines that will highlight the contours of the glass object.
In reality, when photographing glass, all three properties of light come into play (transmission, reflection and refraction). It’s a fun exercise, but there are some challenges. Fingerprints, lint, dirt and dust will all be clearly visible in the resulting image, especially in white-line photographs. Clean glassware and working environment will aid in reducing the amount of time spent removing dust from the image with Photoshop!! Not all glassware can be used; glass objects that are very thick, highly opaque or darkly coloured will not photograph well. Be careful of extraneous light sources; don’t spend hours on the perfect setup only to realize that you forgot to turn off the studio’s overhead light or forgot to close the window blinds!!
For more detailed information, and more complicated setups, see this article on the Sekonic web site.
If you have questions, please email me here.