Size of actual film with wood holders or even modern holders and film flatness

[audioexcels]

I am curious about the actual size of the film that is supposed to go into wood holders. Take for example some 6.5X8.5 holders or just regular 8X10 holders. When I measure the surface area of the film to be inserted into the 6.5X8.5 holder, it is more like 6X8 or so...give/take, in spite the GG is 6.5X8.5.

I am curious how one can keep film flat in these holders when the sizing is not the same as the GG, in spite the holders are made specifically for the back?

Same goes for 8X10 film. I have not had an 8X10 holder, but what do people measure the actual film size that is inserted into the holder and how do holders keep the film flat?

I need to take some measurements later tonight, but even a half plate back that measures 4.75x6.5 on the GG has film area on the holder at roughly 4.25X6 or so. Again, need to take measurements.

[David A. Goldfarb]

Sheet film is thicker than medium format film, so it stays pretty flat on its own. If one has particularly high flatness requirements, there are vacuum holders and adhesive holders that are better than standard holders, but for most purposes, regular filmholders seem to do the job.

[Vaughn]

4x5 film is about 1/16th of an inch smaller in each direction, same thing with 8x10 film. There has to be some play, or else it is a real sob to get the film loaded in the holders.

As far as GG is concerned -- measure the size of the opening it sits on...not the actual size of the GG itself.

Vaughn

[David A. Goldfarb]

The nominal film sizes were originally plate sizes, which were really the nominal size. Sheet film had to be slightly smaller to fit into film sheaths that adapted the plate holders for film.

[audioexcels]

Back to this question. I have done a lot of measuring lately and I am coming up with what is basically 6 1/8" by 8 1/8" for my whole plate back. GG is of course 6.5X8.5. Basically, you can get a 6X8 sheet of film in there easily. What I'm confused about is how this is possible when a 4X5 is indeed 3 7/8"'s X 4 7/8"'s, a 5X7 should be 4 7/8"'s by 6 7/8"'s, but why isn't the full plate more like 6 3/8" by 8 3/8"??? with 6X8, I'm really only gaining another 1" which is a nice looking piece of film, but not exactly what I had expected.

Anyone with more experience on the actual measured area that the 5X7 sheet gives you?

Thanks!

[sanking]

Anyone with more experience on the actual measured area that the 5X7 sheet gives you?

Thanks!

Several 5X7 films I have measure 126mm X 176mm. That is 4 15/16" X 6 15/16".

Sandy King

[audioexcels]

Several 5X7 films I have measure 126mm X 176mm. That is 4 15/16" X 6 15/16".

Sandy King

Sandy,

Do you recall what your whole plate measured out to be? A curious question, do you know the best person to go to for a custom 5X8 back and holders made for the back?

Thanks Sandy!

P.S. I just found a thread about the Lotus holders which are the same surface area of film as my whole plate holders. Just seems like that extra bit that gets cutoff would pose a problem when seeing a whole plate GG that is just slightly larger than what you would see with a 5X7 or 4X5. I wonder how difficult it would be to just cut down 5X8 and then cut 4X8 and 6X8. Seems like a nice spread of image sizes...and then find a cheap Ikeda or Nagaoka 5X7/4X5 for my 4X5 shooting.

[Nick_3536]

S&S might be your best choice for custom holders. -)

OTOH I wonder if the cost of a custom back and holders might get you pretty close to a new 5x8 from Chamnoix.

[sanking]

Sandy,

Do you recall what your whole plate measured out to be? A curious question, do you know the best person to go to for a custom 5X8 back and holders made for the back?



If you already have holders Richard Ritter could make you a custom 6.5 X 8.5 back to fit your 7X11 camera, so you have two formats in one camera. I do recall that you mentioned having a 7X11 camera, right?

If not, RR could make you a 6.5 X 8.5 back for an 8X10 camera.

Sandy