Photographing Glass

Rev. ... 2002-05-29, 2003-03-06, -07-27,2006-01-30, -02-13,
2007-09-30, 2008-04-17, -11-29, 2009-06-20

This page is a few notes on photographing glass with examples. I am not an outstanding photographer, but better than many and I try to pick up good habits and look for good practice.

Photographing glass is more of a problem than it might seem because glass can pass light in so many ways, not just the usual matt reflection we experience from people's faces and clothing and the surfaces of buildings and nature. A piece of glass can reflect light from the surface, bounce light around inside, carry light from the back to the front, subdue light by translucency, and block/reflect light with opaque colors. Clear glass with curved portions can pick up/reflect the surroundings and make that part of the glass. Even glass that can not be seen through may pass light.

One debate the starts arguments about photographing glass is the color or lack of it in the surroundings and the light source. There are people who believe that the best way is to surround it with black and hit it with light. This produces some spectacular images, but is, to my mind, hardly the way people display their glass. The goblet photographed below at Corning represents a variation on this style - dark surround with a pool of light behind . Many people object to using colored light on glass, saying it distorts the colors of the glass, and I generally agree. It is possible to surround glass with diffuse light, so all of the reflections are white. It can be posed on clear glass, so the immediate background is far enough away to be out of focus.

Color film is rated as to color temperature, referred to in shorthand as Daylight, Tungsten, etc., and specifically with a temperature like 3200°K. The higher the Kelvin temperature the more blue in the light, just as a cooler flame is redder and hotter flame is bluer. If a color film (or a digital camera, see below) is not matched to the light source, then an overall color tone is added to the picture which distorts the colors. Tungsten balanced indoor film used outdoors will have a blue cast, daylight film under fluorescent will have a green cast. These can be corrected with color filters, but that topic is well beyond what I want to do here and it is certainly cheaper to just match the film to the lighting conditions.

If a specific high quality film is to be used, then among the choices are buying light sources that match the film and buying voltage supplies that boost or drop the cooler temperature. Photographers operating at this level should have a color temperature meter. In the Corning setup, Variacs raise the voltage to increase the color temperature of the lights.

The four pictures below were taken with a digital Nikon CoolPix 995 using opaque white plastic as background and overhead lighting by a halogen bulb in a fixture. The two with the blue white tone were taken with onboard small flash added - thus the halogen shadow to the left is washed out and a darker shadow is behind the piece. The two with the pink tone were taken with the halogen (and a room light on ceiling to right rear of camera) only. Stronger shadows, better definition. In terms of color of the pieces, the upper is closer to the original glass. The camera was mounted on a monopod because exposures were long for hand held - 1/8 second for halogen only.

This is my outdoor photo rig with a picture taken using it. It is modeled after the Corning rig below, scaled down to fold for storage. I welded a 1/2" (12mm) square tubing frame with pivots at the lower corners so it folds relatively flat in 2x4 feet (60x120mm) The white panel is Plexiglas sanded one side (ordered that way) which is held by spring clamps to the frame (not drilled holes) Originally, I expected the plex to sag more than it does and pull the vertical frames to position. As it is, I add a rope to keep the frames in position and bend the plex to level out the bottom. The white background reflects light through the glass. What I have not used so far is either key lighting (low level accent) or back lighting through the plastic. This image was taken on film and either scanned in or scanned to disk at the time of processing. Since that time I have used the same rig with my Nikon 995. Sanded white Plexiglas is available at most plastics supply houses "white Plexiglas sandblasted F95"

2002-05-15 [query on photographing a glass chain.]   I would suggest the following as a non-permanent way to take a pretty good picture of glass. (See note* at the end about location.) On a sunny day, preferably in mid afternoon so the sun will be over your shoulder, but not too low, take a clean white sheet outdoors and tie it up at the corners facing the sun and just high enough so the bottom can curve toward the camera on the ground. This will form a seamless background reflecting light into the glass.
Run a light white string or rope, or clear monofilament used for fishing or hanging pictures, across the scene so you can hang the chain over it, bunched up.    Set the speed on the camera as high as you can, so the lens is open as much as possible, and get as close to the glass as possible - these two steps will reduce the depth of field so the white background is blurred, more or less, so it doesn't show as a sheet. Take pictures from varying angles so the sun is seen as striking the glass in different ways.
* To use the sheet and rope/string, you clearly have to have two sets of places to tie off - sheet and line a couple of feet in front - and this may be the hardest part. Two clothes lines work if far enough apart. Trees or fences in the right places may work. Two cars parked several feet apart, with the sheet tied to or trapped in the tops of the windows/doors and the rope for the chain tied to the rearview mirrors or antennas may work. If it works for you do it.
If you can get a piece of clean window glass or Plexiglas, you can put the edges of it on two somethings (chairs, stools, boxes) and lay the white background on the ground, laying the chain on the glass and shooting down at it. You may wish the sun higher in the sky for smaller shadows from the supports.

One of the problems photographing glass in indoors that is not mentioned above is the size and shape of reflections, including the various lights, the camera and the photographer!! The usual recommendation is to diffuse the light sources by putting a white translucent panel between them and the glass - including a white tent. Another method is to put a dark panel or cloth up and put the camera lens through the barrier so only the dark surface is visible in the glass. In the Corning setup, the reflections are controlled by surrounding the lighted area with dark and using small snouted lights positioned to avoid reflections. Paperweights are notorious for showing a highlight at the light source. Paul Stankard in this image paperwts.htm#STANKARD places the round highlight at a decorative point on the piece. [Note that looking for the shadow(s) and the highlight can locate the light source(s.)] In a book of his early weights, every single piece was lighted the same with a window shaped reflection on the upper left of the weight. Whether a window or and umbrella diffuser (square umbrella, reflecting light inside, white over opening, crossed braces give four pane window effect) a lot of light from one direction and well placed white panels to fill in shadows can work well - these were probably photographed on a sheet of glass so the background was blurred and light could enter the pieces from the bottom. 2006-01-30

This document photographing stand was put together to photograph the book shown laying on it, which has pages too big to scan on the scanners we own. After rather too much post processing, I get black and white images that separate OCR software will accept. It can also be used for photographing glass

A feature of the stand is that is comes apart and the pieces fit inside the 1'x2'x3.5" base. The two side arms are carefully fitted to the inside and are held by 1/4"-20 machine screws and T-nuts. Different mounting holes permit different angles for the arms, which are 1x2 with 1/4" plywood panels glued across the top. The outlet strips with plug in sockets are each glued to smaller plywood pieces which are bolted to the arm pieces. Aluminum reflectors throw light back down from behind the bulbs and have a bent edge to fit between the two plywood pieces. Two 1/4" plywood panels fit to form the photographic surface and are just wide enough to fit in the base and so are notched to fit around the various arms. The camera mount is two pieces of 1x2 held at a right angle with 1/4" plywood gussets. Note that the mount is off center to the right because when my camera is mounted the lens is to the left. (Can't show that because the camera is taking the pictures.) The mount must be adapted to each camera. My Nikon 995 has a pivot in the middle so the body with the tripod mount can stay upright while the lens points down (as used here), away, up, or back at the photographer (self portraits.) A digital camera with a pivoting screen but with the lens fixed at right angles to the tripod mount would require a vertical mount while a traditional SCR viewed only from the rear gets more interesting to use. When the mounting arm was centered and the lens off center part of the type was lost in the glare from the more direct reflection from the bulbs. For even lighting the reflection line from the lens to the bulbs must not fall on the page. Moving it over solved the problem here within the original design; wider spread of arms could also be done. 2006-02-13

I wanted to photograph fused glass panels as if they were in a window, but with more control and less cleaning than using an actual window. It was an immediate idea to make a small window, but took a bit longer to hold it up. I had two basic adjustable height stands that were used for many purposes in my shop. (left). They sit nicely on concrete with 3 adjustable feet each, but on grass they are stable only with applied weight, thus the gray board. The basic structure is 1" square steel tubing with 3/4" square to telescope inside. Nuts are braised to take a bolt to fix the height. I drilled and tapped some additional holes in the top of the T and made an elbow (upper right) to be fitting and tightened in the T top.

It was drilled and tapped to provide fixing of the T from the other stand. Aluminum plates were roughly cut from 1/16" bar stock and drilled off center to hang upright. One pair fitted to a 3/4" sliding bar for top bracing and the other used an existing center hole for the bottom. On the right is shown the finished frame installed between the sliding bars. A wrench is used for tightening the various 1/4" hex head bolts instead of putting handles on each. The glass being photographed is rested on a clear plastic panel which rests on a support bent from 1/8" aluminum wire pinned to holes in the side frames. The unit is obviously side and top heavy.

The usefulness of 3/4" welded to 1" tubing to make sliding fittings should be obvious. Less so might be the fact that the 1" will take 1/2" (nominal) thin wall conduit, which can be used to extend the base by several feet or make a long hanging rod at the top.		The glass panel was made from an existing piece scrounged from an abandoned popcorn popping cart. The frame was made from 1/2 x 3/4" molding and 1/2"x1/2" wood angle I had on hand from previous jobs. The angle fits over the glass and 2 screws on each side hold the glass in place. Both molding and angle are mitered, the molding being nailed an glued - a nuisance but stronger. 2007-09-29
In use, I found several problems I was able to deal with, somewhat awkwardly in a few cases. Because the sun was to be behind the window, there was a very strong reflection of my face and shirt. This was solved by forming a narrow frame to rest on the top of the window, be supported behind me, and be covered with a black sheet to shade the area, me. and near side of the glass. The unit was already top heavy and this cover made it extremely sensitive to wind, so it fell and I lost a piece of glass (later re-fused). So I put a wooden plate under the stand, weighted the stand and put a piece of 1/2" conduit through the T of the stand to give it a wider base. Because everything is light, I can still shift to change the sun angle and background. 2007-12-03.
In one of the first tests, the window shot looks like the left while the stand shot is at right. One difference is that almost all the light in the window shot is coming from outside into a fairly darkened room, while this side of the stand shot is reflecting all the sky behind the camera plus any light objects. A shade or dark surround may also help. Because the sun is facing the camera, reflections from the photographer are severe.