35mm f2 Biogon issues?

[adam satushek]

Hello, first post on this forum. I'm getting back into Leica after being away for about 8 years. Been shooting Mamiya 7ii, but my main camera will always be 4x5.
Anyways, I acquired a used 35mm f2 Biogon to use with the M4-P I just picked up. I got it from a dealer I trust, paid less for it than a new f2.8 Biogon-C, and it also came with a hood which is nice.
However, I have a few concerns. There is some slop in the focus. By that I mean that when I change focus directions quickly (like while fine focusing) there is a 'knock.' It is not audible, but I can feel it in my fingers. It also focuses nicely (other than the knock) while the camera is horizontal but once its vertical the focus become much stiffer.
My questions are as follows:
Is this to be expected with a used Zeiss? Do similar Leica lenses have these issues? The only Leica glass Ive really used was the 35mm Summicron and 50mm Summilux I had previously and I do not recall these issues.
Would a CLA be likely to fix these issues?
Should I just buck up and accept that the lens may not be perfect but the image quality is still quite nice and its like 1/2 the price of an old summicron?
Should I return it? Ive had it a couple of weeks, and spoke to the dealer about it. And while past the standard return period they said I should shoot with it for a few weeks and see how I feel. So I shot with it for a few weeks...but still don't know how I feel.
Sorry for the long post...but any advice would be greatly appreciated.
Thanks,
Adam

 

[jsrockit]

Unfortunately, you've encountered the Zeiss "wobble" issue. You can either have it serviced or use it as is.

 

[Charles S]

I have a 35mm f2 myself, and it does not have any of the issues you descibed. Focus is smooth, horizontal and vertical. I would send it to Zeiss to have it fixed and get it calibrated in the process as well.
Good luck

 

[adam satushek]

Thanks for the responses so far. Yeah I have heard of the Zeiss wobble issue...is this really just a Zeiss specific problem? Or do similar Leica lenses display it too?

The thing is I can still return the lens...so I'm not sure I would want to send the lens to Zeiss to get serviced. I imagine this is expensive (anyone know how much?) and at a certain point I would just prefer to buy a new one. Though if I were to do that I may opt for the f2.8 Biogon-C....

Anyway, thanks so far, and any additional advice or comments are of course welcome.

 

[bobbyrab]

I would return the lens, most wobbles will be repairable but not always, I had one that Zeiss couldn't repair and Zeiss to their credit replaced it, but I wouldn't knowingly buy one if it had any issues. I think they're great lenses though and have three now, but all are lateish serial numbers, I figure whatever the cause was, Zeiss will have made changes to the lens build to stop the problem, it must have given them grief.

 

[Tom A]

I just Loc Tite'd my 25f2.8 Biogon. It was wobbling a bit (cold weather probably stiffened the grease in the helicoil). It is easy to tighten the assembly - but the earlier Zeiss ZM lenses used the "wrong" lubricant" and it can cause the retaining ring to slowly unwind. Not a big deal - but whoever you bought the lens from should have pointed it out.
My 35f2 and 28f2.8 has no wobble - the 21f2.8 is beginning to develop it so I will unscrew the ring and add some LocTite to that one. It seemed to have affected the first, early batch only - and cold weather affects it too (grease stiffens up). At least it is not as bad as my 21f3.4 Super Elmar that unscrewed itself and shot out of the lens barrel and landed on a tiled floor!!!!! Minor dent on the back ring - no other damage.
Both Leica and Zeiss use a fairly "deep" ring and it is very tight against the rear lens module - and the friction can slowly unscrew it.

 

[semilog]

Haha. My gen IV 50 Summicron unscrewed itself but never spontaneously disassembled. Sheri fixed it. Have had no problems across three ZM lenses though.

 

[adam satushek]

Hey everyone, just wanted to say thanks for your advice. It was quite helpful. I have sent the Zeiss back to the shop. I was kind of on the fence about the 35mm focal length anyways...my first Leica lens was a v3 or 4 Summicron (can't remember) and I loved it, but since then I have started preferring 150mm in 4x5 format over the 135mm I used to prefer. (4x5 is my main format so I use those focal lengths as my reference). So that, and from looking at the negs I shot with the Zeiss 35mm I decided I wanted to get a 50mm first. And as I was talking to the dealer I got the Zeiss from on the phone about sending the lens back, a perfect 50mm came in that they are now going to exchange for me (plus a little extra cash). Its a 50mm Summicron, the Canadian one with the non-concaved focus tab built the year before the M4-P its going one. So, while early 80s Canadian Leicas are probably not really collectors...I kind of like that they match and it will be a great user kit.

Anyway, thanks again for all your advice, it made my decision much easier.

 

[redisburning]

hmm well that's an interesting choice.

but it's one I understand. I just shoot 50mm in 35mm and 150mm in 4x5; every time I think about shooting another focal length I put it on the camera and just instantly regret it.

the v4 cron is a good lens although I would and did choose the ZM planar. however, given that you had this issue your choice of the Leica doesn't surprise me.

happy shooting. please post more and share your photos in the future.