AVENON (KOBALUX) 28/3.5 Fokus way off ...

[maddoc]

... the focus of my AVENON 28mm is way off, only usable as scale focus lens. I think it must be due to a wrong assembling of the focus helical or it has been twisted completely out of correct position.

Has anybody tried to adjust such a lens himself or know a good technician for this work ? The company making the lens has closed 9 years ago, apparently so not of much help.

Thanks,

Gabor

 

[raid]

My 28/3.5 has correct focusing. Your lens may be damaged somehow.

 

[jsrockit]

Perhaps Japan Exposures can help you?

http://www.japanexposures.com/services/

 

[John Shriver]

First check. Focus lens to infinity position. Measure projection of rangefinder cam from mating surface of lens mount. If it's not 7.5mm, that cam is in the wrong position.

I'd expect anyone used to working on LTM lenses can work on this one. They will have the right measuring jigs, and understand the collimation and calibration issues.

 

[maddoc]

Thanks for all the tips and comments so far ! 7.5mm cam - flange distance at the lens was new for me, I will find me a vernier caliper and check. Asking Dirk from japanexposures.com is a very good idea too! 🙂

 

[maddoc]

Jon,

thanks for the link ! I have never hear about this company in Kobe but maybe worth a try.

 

[PMCC]

You could try asking Dante Stella, a member here. Way back when, he was a reseller of the last batch (3rd generation) of 21mm and 28mm Kobalux lenses and knows a lot about them. Regrettably, I returned mine to him because of some minor adjustment issue that later turned out to be an easy fix -- in light of the optical performance and good price (then), I should have let him walk me through the fix and kept the lens. But I'm a mechanical wuss and didn't have the benefit of 20/20 hindsight.

 

[maddoc]

Asking Dante would indeed make sense, too !! I had read his small reveiew about the lens.

I think that the AVENON28/3.5 is not a to bad performing lens, especially at that price so adjusted RF coupling would be helpful.