expanding back from camera ( small ) to mate with back ( bigger )

[jnantz]

is there any best way to make a adapter that
can mate a larger back to a camera?

i figure its "whatever works works" but maybe
there is a best way to do it ...
does the adapter have to be a certain distance from the camera
to assure it won't crop the negative ?

thanks !

[Bob Salomon]

is there any best way to make a adapter that
can mate a larger back to a camera?

i figure its "whatever works works" but maybe
there is a best way to do it ...
does the adapter have to be a certain distance from the camera
to assure it won't crop the negative ?

thanks !

You have other problems to figure out. Will the lenses from the current camera cover the larger format?
Does the current camera have a long enough bellows draw to use with lenses for the larger format?

[jnantz]

hi bob


i've got that all covered. they are both the same format
the lens and bellows have no issues either.

thanks

john

[Michael Roberts]

John, see ideas in this thread: http://www.largeformatphotography.in...expansion+back

Yes, your larger back will have to be a certain distance to avoid vignetting--less so for shorter lenses, more so for longer lenses...

[Tin Can]

Draw triangles on paper to visualize what you need, then a little geometry will get it exactly.

It's fun 'homework'.

[jnantz]

michael and randy,
thanks !

i'm not really going from a smaller format back to a bigger one or visa versa ..
they are both the same format, even made by the same company! but
because they are different models, the backs connections are different
it seems to be a few cm off so the back and the camera won't "mate"
its kind of like trying to use a 5 3/4 square lensboard on a camera that takes
5 5/8 boards, close enough to look like it might fit, but big enough to be annoying.

john

[Bill_1856]

I use a 5x7 extension back on my 4x5 Nagaoka. Works beautifully, but any lens longer than 210mm cuts off about 1/2" on each side, giving a 5x6.5. (Just like Paul Strand).

[Drew Bedo]

The issue is not entirely clear to me. I am guessing that the "smaller" camera is complete except for a GG back, while the available GG back is for a similar camera of the same format, but it is a different model with different dimensions. Perhaps this adaptation should be done by a professional camera shop.

Or maybe something involving a lot of gaffer's tape.

[jnantz]

thanks drew.
i am not affraid of tape ...
typically i use WIDE black masking tape
to attach a roll film adapter to my graflex slr,
and make box cameras, barrel lenses and paper holders out of board and ... tape ..
and currently have a 11x7 back attached to something using masking tape
i was thinking last night and if i could make some sort of large bead of a DRY doughy substance
that i can use as a big gasket .. that will get hard and form the light trap and mate the 2 backs together
( and be removed when i want to use something else on the camera ) i would use that in a heartbeat ..
i was thing of that doughy-stuff i made a relief map of the USA on a sheet of cardboard when i was in grammar school
no idea what it was, or if it is too "wet" to mold on the back of a camera and camera back but
it is just something like a step-up /step down ring i'd need ... maybe i can find some memory foam, wood putty ?
seems less "goey" ...
i'd rather not get a professional involved i like ramen noodles but not enough to eat them for a year.

john

[Randy]

I had a 5X7 back from a different 8X10 camera I wanted to mate to my 8X10 camera (it was a tad larger). I had a carpenter friend plane it down to the exact dimensions as my 8X10 back - took all of about 30 minutes for him to do it. I took it home, painted the now bare wood matte black, replaced the corner pins (that set in the camera rear standard holding the back in place) and it was ready to go. I could have done the work myself with a wood rasp but it would have taken a lot longer and probably would not have been as exact. This may not be the information you need though...