View Full Version : Is it possible to improve Apo Ronar performance at infinity?

15-Apr-2013, 16:00
Any of you know if it is possible to improve an Apo Ronar performance at infinity adding shims to espace both lens cells?.
I read (possibly in this forum) that the RD Artars and Docter Apo germinars improved their performance at infinity using shims between the shooter and lens cells. Thanks in advance for your valuable info.

8x10 user
15-Apr-2013, 18:16
I think you would want to remove the shims or use shorter ones but not all Ronars come apart.

Ken Lee
16-Apr-2013, 01:24
See http://www.largeformatphotography.info/forum/showthread.php?84077-Rodenstock-300-APO-Ronar-f9-optimized-for, which you may be familiar :cool:

16-Apr-2013, 08:10
Hi Ken: Of course I'm familiar with it. In this post I was thinking in my Apo Ronar CL 600/9 in Sinar version (Apo Sinaron 600/9 MC). My 240 and 480 have one shim each. They are excellent performers at infinity, especially my 480, But my 600 is not as crisp as my 480.
I saw reciently an ebay auction of an identical 600/9 in the Sinar version, which was sold at an astronomical price. The seller showed a photo of the lens disassembled and there were two shims. I disassembled mine and there were no shims, so I though mine was not complet or just optimized for 1:1, and I wanted to know if I can improve the infinite performance adding these shims. Anyway, my 600 is OK, but not stellar as my 480 is.

Brian C. Miller
16-Apr-2013, 08:40
It could be possible that your 600 is missing its shims. The easiest way to figure this out is to unscrew the lenses a bit, approximately the distance that a shim would give you, and see if that makes a difference. Also, you could contact Rodenstock and just ask them.

16-Apr-2013, 13:03
You have me scratching my head a bit. I have a 300 APO Ronar that was designed to go into a shutter, but there are no shims. Does anyone know if there are supposed to be shims for this lens? I can't imaging it being any sharper than it already is.

Edit- I just read the other thread referenced above. I guess mine would be optimized for 1:20.