How best to mask ground glass to change aspect ratio

[Christopher Condit]

For a long time I believed that the aspect ratio of a camera was not really important, since you could always crop the print to whatever shape worked best. Then I acquired a Mamiya TLR, and proved myself wrong: I found the square glass quite inspiring, giving me a bright new view of the world.

I'd like to try masking my 8x10 down to 8x8, since maybe I will benefit from a square outlook: just cover up two strips of 1x8 on the ground glass, expecting to crop to square in the darkroom. What are the best materials and method for doing this? Of course it has to be able to go on and off repeatedly, easily, with no damage to the camera. I don't require absolute precision.

TIA,

[Pat Kearns]

If I understand your question correctly, you want to mask the ground glass of your 8x10 camera to 8x8. The easy way without damage to the camera is to use a black grease pencil. They can be obtained from office supply stores for $1 - $2. Draw your lines on the ground glass. They can be cleaned off by just wiping with a cloth.

[Tony Galt]

At stationary or drafting supply stores you can find very narrow black tape meant for use in drawings that adheres nicely to the inside of the ground glass (I don't know about fresnel lenses). It is opaque and stays put. There may even be a dotted line version available. It comes in several widths. I put a 6x7 frame on a ground glass to use with a roll film holder that way.

[Leonard Evens]

Maybe this doesn't answer your question, but after years of using TLRs, I got quite adept at visualizing how an 8 x 10 print aspect ratio would appear after cropping in the square frame. One disadvantage of any explicit cropping mask is that it doesn't allow you to shift. Of course, you can do that with the camera, but why bother if the desired cropped section is already visible in the frame except for masking?

[R Miller]

Can't say that I have tried it, but consider black gaffers tape. I wouldn't hesitate to try it on my Sinar anyway. As long as it isn't left on for an extended time or subject to very high heat, it should come off with little/no residue. If uneasy with gaffers directly on the glass, Scotch and others make certain tapes that leave no residue and you could color that with a black marker or put black gaffers on that to reduce reflections. I often use Scotch "Artist Tape for Watercolor Paper" to hold negatives/chromes on a flat bed glass and it has sufficient holding power while leaving no residue.

Best regards,

[Ralph Barker]

Random thoughts (aka hair-brained ideas):

1. scraps of mount board, taped in place - better if black?

2. black gaffers tape, as previously suggested, but it's awfully sticky

3. regular masking tape

4. low-tack painters stripping tape - less residue

5. strips of that static-cling plastic material used for signs and such (no residue at all, you'd just have to carry along the backing material that it goes onto for storage - not sure where to find it though)

[Christopher Condit]

Leonard, you make a good point about the mask requiring unnecessary shifting. Therefore I think a line would be better than a real mask -- maybe I'll try a grease pencil.

Thanks everybody,

[Jason Greenberg Motamedi]

I use a high-quality black masking tape cut into thin strips (~1mm) on my ground glass to demarkate different sizes I use. It works well, and is easily removed. Grease pencil also works fine, but is slightly more difficult to remove.

[Jeffrey Goggin]

Since I'm also shooting "8x8" with an 8x10, I addressed this problem by simply using two strips of blue masking tape (the more expensive stuff) across the top and bottom of the ground-glass. Unlike gaffer's tape, it's translucent -- so I can see through it somewhat -- but not so much so that I can't also ignore it when I choose to do so.

[Robert A. Zeichner]

What I would suggest is getting some neutral density gel of .3 or .6 values and glue it onto the outside of your gg with tiny spots of transparent aquarium cement (silicone adhesive). You can apply the cement with a toothpick, as you will not need much to do the job. The ND gel will allow you to see what's beyond the desired 8x8 composing window, but will also provide a defined boundry. Of course there is always the possiblity of making a composing card through which to view. And a third option might be to remove the gg and with a very sharp, hard pencil, scribe lines onto the ground surface and then make a series of angular hatch marks on the two 1" wide strips left and right of the 8x8 area. This, by the way is how viewing screens in professional motion picture cameras are often treated.