Do It Yourself
Make Your Own Custom Ground Glass

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Use these inexpensive off-the-shelf materials to make a replacement view camera ground glass. The $2 picture frame yields a piece of thin 4x5" glass, and the $6 can of Painter's Touch Frosted Glass Finish spray (see text) produces a satin-like "ground" surface. Optional grid overlays are easy to make on 3M Transparency Film with a PC and laser printer.
Photos © Tom Fuller, 2000

This month's project is a simple way to replace or customize the ground glass of any large format camera. Only a few inexpensive materials are needed to make the glass itself, but you will need the use of a computer and a laser or ink jet printer for the optional grid overlay. Each piece of glass costs only a couple of dollars and can be made in an hour or so by anyone with basic do-it-yourself skills. If you are not computerized, there are office support stores where such equipment, along with technical assistance, can be had on a per-hour basis.

The technical trickery lies in one product, Rust-Oleum Painter's Touch Frosted Glass Finish, an aerosol available in hardware or home improvement stores. This fast-drying material creates a translucent effect for decoration or privacy when sprayed onto clear glass, but we will use it to make the rough side of the ground glass on which the image is focused. Although this finish was traditionally produced by grinding the glass with abrasive paste, etching it chemically or blasting it with sand, anything that renders one side semitransparent serves the same purpose. So far I have seen only Rust-Oleum's product, but other manufacturers may offer something similar.

Two thin coats of Painter's Touch Frosted Glass Finish applied to one side of the glass produces a smooth, translucent focusing surface. Follow the directions on the can and spray side to side with even strokes. Application uniformity is important for accurate focusing, so practice first on scraps of glass or other material. The "grain" of our do-it-yourself ground glass is coarser than that of a factory-made glass, but it costs far less, especially in very large or specialty format sizes.
A source of thin glass is just a few aisles away in the picture frame department. Carefully measure the recessed area of the camera back into which the ground glass will fit, then select a similarly sized frame. Check several different styles with a metric ruler, as the actual glass size varies considerably. Although you can sand down the edges of an oversized glass to fit the camera, it is generally easier to build up the ground-glass receiving area with small strips of wood or cardboard to make it accept a slightly undersized piece. Do not use "non-glare" glass or acrylic material.

You can cut the corners off with an ordinary hand-operated glass cutter if you wish, but it is a lot easier to leave them alone. Cut corners allowed the photographer to look into the camera from behind and quickly see if the shutter was open (a stopped-down aperture being easy to see if viewed directly even if its image was hard to discern on the ground glass without a dark cloth), as well as let air flow in and out when the bellows was rapidly extended or compressed. Square corners require only that you check the shutter from the front and work the bellows slowly. Clean the picture frame glass thoroughly and apply the spray finish as shown.
3M Transparency Film runs through any laser printer like ordinary paper to make a sharp, black-line grid or format outline overlay for do-it-yourself or existing ground glasses. The artwork can be quickly created with the easy to use drawing feature of any major word processing program. This film material is also available for ink jet printers, allowing the addition of color overlay elements.

The grid overlay, made on 3M Transparency Film, is an option that can be added to this or an existing ground glass. It aids in composition, especially with architectural subjects where straight and level is the order of the day, as well as when a rollfilm back making 6x7cm or 6x9cm images is used in a 4x5" camera. In addition to low cost, making your own grid lets you include only those elements desired and eliminates the visual clutter typical of commercially-made multiple-format ground glasses. Any format can be delineated, by a full rectangle or just corner brackets, and the overlay can be quickly removed.

Prepare the artwork on your computer, with a dedicated illustration package or the drawing component included in most word processing programs. I used Microsoft Draw within Microsoft Word 97 to make the ones shown here, and did each in under an hour. Turn the "Snap To Grid" feature on for straight lines and sharp, even corners, and remember that "Copy" and "Paste" allow a full grid of any size and shape to be quickly made from just a few intersecting lines. Most drawing software is very precise and dimensional accuracy will depend largely upon your patience, but a simple pattern of squares approximately 1x1cm is generally adequate.

Format outlines will require some trial-and-error tweaking of the rectangle with "Snap To Grid" turned off and, as the 81/2x11" transparency film is somewhat costly, a few test prints for measurement on plain paper. Keep lines as thin as possible to prevent them from becoming obtrusive when viewed with a focusing loupe. Cut the finished transparency sheet to size only after centering the outline over the installed ground glass. If you have a computer but not a laser or ink jet printer (color ink jet transparency film is also available), create the artwork and take the file on diskette to a copy shop for output.

Slip the grid under the ground-glass hold-down clips, tape it in place, or sandwich it between the ground glass and a thin, clear top glass. Tighten the hold-down screws gently, as excess force will, quite literally, shatter your efforts. This method can also be used for making ground glasses for medium format cameras, although ordinary picture frame glass may be too thick for the hinged retaining frame used in many. Try a glass shop, science supply store, or stained glass studio for thinner glass sheets.

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