Here is a link to the specs for standard film holders including 8x10:
http://home.earthlink.net/~eahoo/page8/filmhold.html
And, here is a link to some non-standard film holders, including 4x10, as used by KB Canham:
http://www.canhamcameras.com/Film%20Holder%20Specs.html
Note that the Canham 4x10 film holders have become the de facto standard. There is another, older size 4x10 holder that was an X-ray film holder that is smaller and hard to find. Also, I believe Lotus 4x10 film holders were similar to Canham holders, but slightly different. I would suggest standardizing on the Canham-type film holders as they are more common. There is one or more articles on the LF Home Page about 4x10 film holders and related gear.
Keith Pitman
Thanks Keith. The Canham link is a new one for me - useful stuff.
Yes, it makes sense to follow the more common standard on the 4x10 so I'll pay close attention to the Canham numbers.
I saw the piece on 4x10 film holders by Kerry Thalman a while ago, and it's one of the reasons I decided to give 4x10 a go. Not the easiest of formats to get the composition right but when you do, it works really well.
Thanks again,
Duff
Am in the position to be able to check the measurements of quite a few 8x10 film negatives dating back to maybe the 1930s. Maximum size is never over 8"x10" Minimal size is about 1/16" less in both dimensions, with the longer dimension in one case 1/8" less than 10". So much for precise standardized film dimensions....
Hah! Yes indeed. I guess there's a 'margin of error' in these things regardless of so-called standardisation. If I factor a minimum of 1/8 inch into the design then that should cover most things - that would work out as 1/32 inch (about 0.8mm) for each side of the holder.
Thanks Greg.
Duff
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