barrel and other lenses and thead size

[dr5chrome]

Hellos - '3' Qs if I may..

1. Im having difficulty finding the flange thread size of the standard Graflex RB 4x5 lens [the 192mm]. My best guess is 57mm ??

2. I was digging in my cabinet and found an old lens I forgot about. cant remember where I got it.. The lens says DOGMAR 1:4,5 F=168mm D.R.P. C.P.GOERZ BERLIN. It covers 4x5, and may cover 5x7. Anyone else know this lens?

3. The actual thread size of the BETAX no.4 shutter? The thread measures 57.11mm but it will not fit 58mm.. [57.5? 57?]

thanks! regards, dw

[Dan Fromm]

The actual thread size of the BETAX no.4 shutter? The thread measures 57.11mm but it will not fit 58mm.. [57.5? 57?]

2.422" x 40 TPI. This from https://alphaxbetax.com/resources/

[dr5chrome]

hmmm. I must have something different, but it is a betax no.4. 2.422" is 61.5mm which is way bigger




2.422" x 40 TPI. This from https://alphaxbetax.com/resources/

[Whir-Click]

Perhaps your Betax has adapters threaded in. A photo would help to know for sure. Without thread adapters it looks like this:

244687244688

[dr5chrome]

244689 Here is what I have. it doesnt seem there is an adapter thread, unless its attached under the face plate. . I have had the face plate off to clean the shutter mechanism. Nothing seems added on. [I could see the work done to put in the flash sync.]. The thread is either 57mm or 57.5

dw



Perhaps your Betax has adapters threaded in. A photo would help to know for sure. Without thread adapters it looks like this:

244687244688

[Whir-Click]

Thank you for the illustrative photo: that is definitely an adapter going from the shutter’s original 2.422" threads to ~57mm. Another way to confirm is by measuring the shutter’s overall thickness. A Betax #4 without any adapters protruding should be 26mm.

It’s difficult to get much mechanical purchase to unscrew adapters stuck with age. I find a strap wrench or very large filter wrench are a good place to start.

244690