From here to infinity.

[Shadesofgrey]

Afternoon all.
Anyone know what the rear lens to film plane distance should be for a Zorki 4/4k with the J-8 set on infinity.
Take care.
B.

 

[Kim Coxon]

Hi,
The flange to film plane distance should be 28.8mm +/- 0.02mm. If this is correct and the J8 is not focussing to infinty, then you need to adjust the shimming in the J8.

Kim

 

[Shadesofgrey]

Hi Kim. I’ve set the flange to film plane as you say, just trying to work out if there was some sort of standard measurement, a starting point if you like, between rear lens and film plane. When I set up my 35mm SLR lenses (as on Rick’s Site) I can roll past optimum focus and roll back, sort of see/feel the optimum point of focus drop in; can’t do that on a Zorki because of the shim. Am I making a pigs ear of this :bang: is there an easier way? How do you set yours?

Thanks for the help.
B. 😕

 

[Kim Coxon]

I use the "2 camera" method indoors. To make life easier I have and old Fed2 with the curtains taken out, a big hole cut in the back door and matt glass screen glued to the film rails. Once the setup is in place, I look through the SLR using a 2x mag hood and a 200/2.5 lens for accuracy. If the subject lens is out of focus, I move the lens out using the normal focus. If this improves things, more shimmimg is required. If not I will remove a shim or put a thinner one in and start again. It is a bit trial and error but once you are in the ball park, you can get a good idea of the shim required and either swap it for a diffrent (easy for me I know!) or fabricate one.

Kim

 

[Shadesofgrey]

Thanks Kim. Now the fog lifts! I use a similar set up to yours for my SLR lenses, and I just happen to have a spare back for a Zorki. Off to get the DREMEL out 😀

Cheers.
B.

 

[Bill K.]

Hi Kim,

Does the 28.8 mm flange to film distance apply to FSU cameras only, or is it valid for all LTM cameras ?

I have a Beesa R with the CV35/2.8 lens and a black J8. I am reluctant to use the J8 because I have read in some threads on RFF that the J8 may not focus properly on the Bessa.

Thank you for any informaion you can provide.

Bill K.

 

[Kim Coxon]

The Bessa's like the Leic's, Canon's and other similar western/japanese cameras were built to the Leica Standard hence the interchangeability of M39 lenses. The FSU ones should also share the same standard but either due to manufacture or a previous history of kitchen table repairs, this is not always the case. In some cases the bodies were adjusted to the lenses rather than the other way round because it was easier and few had multiple bodies as some have today.

They should be no problem using the J8 on the R. When I had an R, I used both a J8 and J3. It certainly won't do any damage even if the lens is out. Generally speaking there is not a problem with most J8's although I have had to alter a couple to get them spot on. The other way round with the J3's and J9's. Most need to be tweaked before they will focus accurately throughout the range.

Kim