Just a word of warning about yet another possible pitfall for those considering the 4x10 format. I have a 4x10 camera that consists of a Lotus 4x10 back and bellows that I have adapted to mount on my ARCA-SWISS F-Line chassis. I have several of the beautifully made wooden Lotus 4x10 film holders that, naturally, work wonderfully with this camera. I just purchased some 4x10 Canham holders to supplement my stock of Lotus holders (with the weak dollar these days, new Lotus 4x10 holders are running almost $420 each - compared to $100 each for the 4x10 Canham holders). Much to my surprise (and disappointment), the Canham holders do NOT fit my 4x10 Lotus back. I found this rather odd, since I have always been told the 4x10 Lotus was designed to take the Canham holders.
The difference is small - I measured several Lotus holders, as well as the four Canhams that arrived today. On average, the Canham holders are about 0.040" wider. Now, 40 thousandths of an inch may not sound like much, but it's enough to keep the Canham holders from fitting in my Lotus back. I also tried the Lotus holders in a Canham camera. They fit, of course, but are slightly loose.
During this process, I also noticed that the location of the film in the holders is different. I'm not talking about the T-distance (film plane distance) which appears to be the same (within reasonable tolerances). I'm referring to the actual x, y dimensions. In this case the actual image area of the Lotus holder is shifted to the right by about 1/4". Not a huge amount, but it could mess up a carefully composed shot if you attempt to fill the whole frame.
One caveat, I have been told by Lotus that my particular 4x10 back is a very early production model. I have no idea if the design of their back or holders have changed over time. Has anyone else attempted to use a 4x10 Canham holder in a 4x10 Lotus Camera?
I may consider having my 4x10 Lotus back modified to accept the Canham holders (but, I'd still have to deal with the image being shifted - in this case, to the left by 1/4"). In the meantime, I would not recommend assuming 4x10 Canham holders will fit a Lotus Camera. So, not only do Canham and Wisner have different size holders for their 4x10 cameras, it appears Lotus does as well. With all three camera manufacturers using proprietary holders, is it any wonder the 4x10 format has never really caught on?