90mm Sun Sola on Fed 1g

[oldrangefinderguy]

Okay, I already knew about the slight focusing mismatch between Soviet 39mm screw mount cameras and standard Leica thread lenses, the former being based on a Ziess standard. But I thought a 90mm with a maximum aperture of f4 might be slow enough to work alright on the fed. Wrong. my test showed that the Sola was off by about six inches when focused to it's minimum distance.
So what is the solution? Is there a solution, or must I only shoot stopped down and/or at further distances? Could this lens be reculminated to focus correctly on the Fed? I realize that this is probably impossible and that the best possible compromise might involve optimizing close focus and letting depth of field cover focusing errors nearer infinity. But is even that possible?
And, how do I find out how to do the procedure? I've done some successful repairs in the past, but I don't consider myself a wiz at camera repair. The lens is not mint or rare, nor is the glass pristine, and it probably doesn't merit the cost of a professional repair man, nor can I afford that route. I'll never buy a real Leica to use it on so keeping it's focus compatible with the LTM standard is not of any benefit to me. I do have a junk Fed 2 body which unlike the Fed 1 has a removeable back, so I could use this body and a piece of frosted glass to test the lens's focus.
Any imput would be appreciated.
Randy

 

[Jocko]

Hallo Randy!

The Zeiss thing is controversial, although I'm inclined to think "there's something in it"... But - assuming you did not use the lens barrel distances to focus - the chances are that this is simply a rangefinder issue. I find the Soviet rangefinders are very sensitive and will often need to be adjusted for each lens. When adjusting the RF accurate close focus is vital: close and infinity focus are set through linked but seperate operations. I expect you already know RFF member Zorkicat's invaluable Fed Zorki Survival site (you can follow his signature link). It will tell you just what to do 🙂


Cheers, Ian

 

[oldrangefinderguy]

Thanks Ian. You might be on to something. The only other lenses I've used on the Fed are the 50mm 3.5 Industar and a Jupiter 12. In both cases depth of field could be covering for the rangefinder being off. I have an Industar 26 with a 2.8 maximum aperature. I'll see if that shows up any error at closest distance. Wish I had a Jupiter 8 in screw mount.