CV 21/4 loose lens barrel

hexiplex

Well-known
Local time
1:41 AM
Joined
Nov 20, 2010
Messages
293
So, last night when I mounted my CV-21 (the "long" version with the barnack-style focusing tab) I noticed after a few frames that the lens barrel had become loose somehow, or rather, the focusing ring had become loose. I can still focus the lens, but it requires that I push down on the barrel at the same time that I pull focus, and focused at infinity (or as close to it as I can get) I can't turn the aperture ring. But at the minimum focusing distance, turning the aperture ring is no problem, but then again, at minimum distance the focusing ring is so loose I need to push it down with the aid of the focusing tab.

Any ideas? A home fix, a repairmans job, common issue?
 
Last edited:
Well if the construction is anything like my VC 35/2.5, with which I had a similar issue (bought "broken", ha! :)), it takes about a minute to fix it by tightening the ring that holds the two parts of the lens assembly together. This ring would be around the rear element. It should be pretty loose and turnable by using a finger nail if I'm right with my guess...

Obviously you should use a proper lens spanner to properly tighten it, I don't have one, I've used improvised tools...
 
Last edited:
Any pictures to help me along the way? And what improvised tools did you make use of? I really want to take this lens with me on my short european roadtrip that I start in a few days.
 
Any pictures to help me along the way? And what improvised tools did you make use of? I really want to take this lens with me on my short european roadtrip that I start in a few days.

I'm afraid not... I don't have a digital camera, nor a macro for my film SLRs, sorry!

However, if you take the lens in your hand and look around the rear element you should see ring(s) with two slots, or cut-outs, each, on opposing sides of the ring. These slots are used to turn the ring with a lens spanner, or as I do a modified long-reach electronic pliers. Try if the ring is loose with something that can reach one of the cut-outs.

In the 35/2.5 there are three such rings, two innermost are to do with securing the rear element and the outmost (third) is the one that keeps the lens body together. Check if any of the ones you can see are loose - none should be.

cheers,

Jani
 
Well, couldn't find any rings or partitions with cut-outs on them unfortunately. Too late to use the lens on my roadtrip anyway as it's already begun, any further tips are welcome though, anything to avoid the expensive bill from Cosina that I'd rather spend on beer.
 
Back
Top Bottom