Quote Originally Posted by JasonC
I have read postings on several large format sites. There seems to be no consensus on whether holders from different manufacturers are interchangeable. On one post, Sandy said 2 versions of 7x17 holders are made. 1st version is based on Korona holders and made with Cherry, and the 2nd version is made to Canham standard with Walnut. On a different post, someone mentioned that AWB and Lotus holders are almost identical in specification. On yet another post, someone mentioned that most of the newly manufactured holders are based on Korona holders. Based on the last comment, could one assume that the S&S, AWB and Lotus holders are interchangeable? However, I could not find any definitive conclusion.

So if I have a 7x17 camera that works with Korona holders, what new holders could I use on the same camera? Are the S&S, AWB, and Lotus holders interchangeable? Thanks.

The holders are almost always interchangeable but the user might need to make small modifications to the back to make them completely compatible, so the answer to your question is, "it depends." Here is what I know.

1. F&S holders are different from all others in that there is a groove on the holder that fits over a raised rib in the camera back to form the life baffle. AWB, Lotus, Korona, S&S have a rib on the holder that fits into a groove on the camera back. As you can see, the F&S holders are the odd man out here, which is why I advise owners of F&S cameras to adapt the back for other style holders, unless of course they already have a good supply of S&S holders.

2. Most 7X17 holders are about 8.5" in width (top to bottom) This includes all AWB, Lotus, and S&S holders that I have seen. Some Korona and F&S holders are wider or narrower. If wider, they may not fit into the back of some cameras, both vintage and contemporary.

3. The last obstacle to a good fit is the position of the rib lock on the holder. For a good light baffle the rib on the holder must fit into the groove in the camera back. If it does not, you *will* get a light leak at this end, which often will be seen at the other end of the film becaue of the angle at which light could enter. If the rib lock does not fit into the groove on the camera back it is nearly always possible to adapt the back by either widening the groove, or by routing out another groove. This is very easy to do and most persons would be able to do the adaptation in lesss than 30 minutes with a Dremel type tool.

With regard to S&S holders. All of our holders are made to ANSI specifications for formats that had ANSI specifications. The 7X17 format (and 12X20 also) never had ANSI specifications. So when we began building and marketing holders we adopted the Korona standard. However, since the Korona standard was not very precise, we settled on an average measurement for width and position of the rib-lock. Most of our holders made before 2006 had these specifications. In late 2005 we adopted the Canham specifications for 7X17 and 12X20, which are BTW slightly different from Lotus. All of the holders we are currently building in these sizes, both cherry and walnut, are being made to Canham specifications.

Hope this helps in terms of a general understanding of the differences. The issue is actually more complicated than the above when WYSIWYG and ET-dimension are concerned, but a real thorough treatment of this would require a long article.