PDA

View Full Version : Tachihara 4x5 – 5x7 step up back



Ginette
28-Jan-2010, 17:15
RE: this topic http://www.largeformatphotography.info/forum/showthread.php?t=58446

For the benefit of all users who might be interested to the Tachihara 4x5 – 5x7 step up back and wish to know if it can fit others brands.

Mr Salomon proposed to measure an original back.

Here mine, a Zone VI model (middle production). Can you post the exact mesures corresponding to the letters. And maybe some pictures of the back.

Bob Salomon
29-Jan-2010, 14:34
THE AREA THAT MOUNTS TO THE CAMERA BACK IS 6 5/8" square. The overall size is 8.5" square. So the part that mounts to the camera is 3/16" too large in both directions.

Ginette
29-Jan-2010, 16:12
THE AREA THAT MOUNTS TO THE CAMERA BACK IS 6 5/8" square. The overall size is 8.5" square. So the part that mounts to the camera is 3/16" too large in both directions.

Thanks for theses measurements.

If the 6 5/8" is the C and D, it can be very easy to remove 3/32" on each side with a router. What is the depth of the "seal step" ("E" in my picture)?
If the 8 1/2" is the A and B, this will need to remove a whole 3/8" on each side, this depend on how the back is constructed. Can you post a photo of the back as I suspect that the one post in the original thread is not a Tachihara but a Nagaoka or Ikeda as Bryan post about.

The expansion back that I have on my Nagaoka 4x5 (same as a Calumet wood field, I think) looks identical to the one that John listed in the original post. I think that it might also fit the Ikeda 4x5. The outer mounting flange is apx. 6 13/16" (173-ish mm) square and the inner "seal step" is 6 3/16 (158mm). There are no pins and the mounting flange thickness is apx. 1/4". Curious to see if it is the same measurements as those that Bob markets through HP - may fit several different brands.
Can you measure also the deep of the mounting flange ("F" in my picture)
Thanks for the info.

Ginette
31-Jan-2010, 13:11
Hello again Mr Salomon,

Can you indicated me also the deep of the unit, ex. from the ground glass to the camera mount (perpendicular, not the side lengh). I think problems with some lens occur because unit is too compact to be in the right prolongation of the bellows angles. RE: problems as described by QT Luong here (http://www.largeformatphotography.info/tachihara.html)
Hope it's clear, sorry for my bad English.

Bob Salomon
31-Jan-2010, 13:24
Hello again Mr Salomon,

Can you indicated me also the deep of the unit, ex. from the ground glass to the camera mount (perpendicular, not the side lengh). I think problems with some lens occur because unit is too compact to be in the right prolongation of the bellows angles. RE: problems as described by QT Luong here (http://www.largeformatphotography.info/tachihara.html)
Hope it's clear, sorry for my bad English.

About 5 or 6" deep but I can't measure it as I am traveling until the 25th of next month.

Ginette
31-Jan-2010, 14:32
About 5 or 6" deep but I can't measure it as I am traveling until the 25th of next month.

5-6" should be enough to not have long lens problem. "Your unit" is probably definitevely deeper that the one posted in the original Sales topic (http://www.largeformatphotography.info/forum/showthread.php?t=58446).
Maybe the QT Luong test was not made from an orignal Tachihara back or the back was corrected since.

Can you confirm also the size you gave earlier are the A-B-C-D ones ? Thanks