Fotoman 5x7 Film Holder - Thickness

Wouldn't you know it... just as we're about to finish up on the molds for our 5x7 Film Holders... a discrepancy pops up...

the ANSI specification for 5x7 film holder thickness is 0.562 inches, so that's what we started tooling for. In the meantime, we picked up samples of various 5x7 holders (no Toyo's though)... none of which have the same thickness, and none of which agrees with the ANSI spec.

Would someone who has a Toyo 5x7 film holder please measure the thickness?

Better yet, would someone be willing to donate a Toyo 5x7 film holder for an autopsy? We would glady return 2 of our new film holders as a thank you for the donation.

No Toyo 5x7 holders here Paul, but I just measured a half dozen Liscos. They ran from 0.503 to 0.515 inch.

A holder's T-depth is critical, but I don't think outside thickness is. Holder thickness can vary based on how thick the septum is. As long as you maintain a seating surface exactly one "T" from the septum, it doesn't matter if your holders are 0.5 or 0.6 thick. I can't think of a camera back that wouldn't accommodate anything in that range.

Sorry, no Toyos.

My Liscos are around 0.509, wood and metal Agfas at 0.575, older nearly all-wood Agfas at about 0.562. All these holders perform very well (I immediately junk any that don't).

Sounds like the ANSI spec was created when the thicker (but lighter) wood film holders were the standard. I prefer the newer Agfa holders, they are not as long and notably lighter than the Liscos, and don't leak like the all-wood holders sometime do.

I agree with Sal, it's the depth to the film that matters---the manufacturer must be free to determine how to balance thickness, strength and weight as best suits their materials.

Good luck with the new holders!

Clyde Rogers

Sal Santamaura said:

No Toyo 5x7 holders here Paul, but I just measured a half dozen Liscos. They ran from 0.503 to 0.515 inch.

A holder's T-depth is critical, but I don't think outside thickness is. Holder thickness can vary based on how thick the septum is. As long as you maintain a seating surface exactly one "T" from the septum, it doesn't matter if your holders are 0.5 or 0.6 thick. I can't think of a camera back that wouldn't accommodate anything in that range.

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Thanks Sal. We tend to agree that while the "T" dimension is imperative, the thickness shouldn't matter. We're simply curious to know what Toyo did, as it's one of the only samples we haven't disected. Curious minds want to know.

0.470

As a bonus: Linhof film-plate, 0.813, a couple of old Fidelities 0,496 to 0,513

(Gives you some idea of the accuracy of my 50-year-old micrometer and my skill in using it, neither of which may be state of the art)

Roger Hicks said:

0.470...(Gives you some idea of the accuracy of my 50-year-old micrometer and my skill in using it, neither of which may be state of the art)

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So Roger is the only one so far that actually has a 5x7 Toyo holder!

I've reviewed my copies of the ANSI spec ranging from 1951 to 1988. There was never any change for "C" (thickness) -- it was always stated as 0.562 inch maximum.

Until Gary Smith initiated a thread discussing the possibility of obtaining 5x7 holders from Toyo I didn't even know Toyo had ever made holders in that size. There was no mention of any in Toyo literature as far back as I could find any. So I can't confirm or refute Roger's measurement of an actual Toyo 5x7 holder's thickness. However, I do have several brands of 4x5 and 8x10 holders, so here are some further data based on research and measurement -- with no more skill than Roger but using a digital caliper -- this morning:

"C" (thickness) of 4x5:

ANSI - 0.520 inch maximum
Riteway - 0.441 through 0.449 inch
Toyo - 0.439 through 0.440 inch


"C" (thickness) of 8x10:

ANSI - 0.594 inch maximum
Lisco - 0.564 through 0.572 inch
Toyo - 0.570 inch everywhere

So it seems that Toyo's thickness is very consistent (like its T-depth) and somewhat or substantially less than the ANSI maximum depending on film size.

I haven't seen a Toyo 5x7 holder, but can comment on differences in execution between their 4x5 and 8x10 holders.

My Toyo 8x10 holders are screwed together, have metal dark slides with metal pull handles, had mat black paint applied around their film guides and aperture edges during final assembly and are substantially heavier than my modern (plastic slides) Fidelity/Lisco holders.

My Toyo 4x5 holders are riveted together, have plastic dark slides with plastic handles, lack any mat black paint (though their design seems to avoid edge reflections that plague Fidelity/Lisco/Riteway holders) and weigh a bit less than their Burbank counterparts.

My preference for the Fotoman 5x7 holders is that they follow Toyo's 4x5 model, i.e. lighter rather than heavier. Roger's thickness measurement seems to indicate that's exactly what Toyo did. I'd suffer a few grams more weight if screw construction can be implemented instead of riveting but want the holder halves to be attached together one of those ways rather than welded.

Sal Santamaura said:

I'd suffer a few grams more weight if screw construction can be implemented instead of riveting but want the holder halves to be attached together one of those ways rather than welded.

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The Toyo is screwed together.

Roger Hicks said:

0.470(Gives you some idea of the accuracy of my 50-year-old micrometer and my skill in using it, neither of which may be state of the art)

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I'm glad I'm not the only one who takes longer to relearn how to use a micrometer than it actually takes to use it to make one measurement!

I suspect my micrometer is also about 50 years old, but since they haven't changed the length of an inch recently, it still works just fine.

Monophoto said:

I'm glad I'm not the only one who takes longer to relearn how to use a micrometer than it actually takes to use it to make one measurement!

I suspect my micrometer is also about 50 years old, but since they haven't changed the length of an inch recently, it still works just fine.

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The only thing that makes me suspicious is that the moving part and its anvil do not line up precisely. They're dead flat and meet perfectly as far as I can see but they're offset, as it were. I inherited it from my father-in-law, so I don't know what sort of life it had before, or indeed, how old it is.

But I've just noticed that the holder in question is half-plate (4-3/4 x 6-1/2 inches) and not 5x7 inch (I've not used it for years, preferring Linhof film/plate holders).

As all other 5x7 inch/13x18cm/half plate holders I have are on the same chassis, as it were, masked for the different formats, I assume the information holds good for 5x7, and as they all go impartially into the same cameras (Linhof, Cambo, De Vere), it seems likely. I apologize for misleading anyone, if I have done so (which I don't think I have).