Author Topic: P6 to F distance?  (Read 677 times)

CardBoardBoxProcessor

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P6 to F distance?
« on: April 09, 2018, 15:13:16 »
High, hoping to make a quick adapter on my 3d printer for proof of concept for a future more advanced tilt shift  adapter. But I need to know the distance from The very rear of a Pentacon 6 bayonet in (male) the the back end of the F mount ring. whats the distance between the two.

Akira

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Re: P6 to F distance?
« Reply #1 on: April 09, 2018, 16:24:35 »
Hi, here you can look into the flange back of all sorts of lens mounts:

https://en.wikipedia.org/wiki/Lens_mount

According to the wiki, the flange back of Pentacon Six mount is 74.1mm.  Nikon F-mount has 46.5mm flange back, so the difference is 27.6mm.

This calculation is, of course, based on the assumption that the wiki datum is correct.  Everyone here should know the flange back of F-mount, though.
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CardBoardBoxProcessor

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Re: P6 to F distance?
« Reply #2 on: April 09, 2018, 20:16:06 »
Ah. I was not aware the definition of the word I was searching for. "Flange back" so that is generally considered  uniform?

pluton

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Re: P6 to F distance?
« Reply #3 on: April 09, 2018, 20:22:25 »
I have seen Flange to Film, Flange to Focus(technically, probably the most correct term), Register Distance, Register, Flange Distance.  There are probably more terms that others can contribute.
Keith B., Santa Monica, CA, USA

Akira

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Re: P6 to F distance?
« Reply #4 on: April 10, 2018, 10:28:03 »
So far as my understanding goes, "flange back" may be more of a common term rather than the specialists' term.

So far as "flange something" is not mixed up with "back focus" (which is the distance between the sensor/film and the tip of the rear-most optical element), the confusion could be minimized?
"The eye is blind if the mind is absent." - Confucius

"Limitation is inspiration." - Akira