VC 40 Nokton: smooth focus possible?

kevin m

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I've owned two copies of the VC Nokton 40 SC, and both were stiff focusing lenses. The second I sent to DAG to have lighter lubricant applied and it came back too stiff as well.

I like the images it makes and the focal length, but it's just too stiff. It feels cheap in focus feel compared to the better Leica and Konica lenses I've owned. It takes conscious effort to move the focus tab back and forth and it spoils the pleasure of the lens, IMO. Is it possible to find a smooth focusing version of this lens, or should I just give up after two tries? :confused:
 
My one and only Nokton 40 started out stiff, but smoothed out noticeably on a trip to (hot) Sri Lanka (but still not as light as my Rokkor 40). Now, however, it's become dry feeling, so it's about to go in for a CLA. I'm hoping it comes back nice and smooth.
 
I understand that the second production run of the 40 Noktons had lighter focus; my SC is fine.
 
Mine feels gummy

Mine feels gummy

Not keen at all on the feel of mine. I think that fact that it has a focusing tab instead of a focus ring compounds the problem. It feels like dried up grease. Have been tempted to put a tiny spot of light machine oil down into the grease, thought it might free it up a bit? I know this sounds like a bad idea, but people are a bit overly protective with these things..
 
Mine were the same way, the grease felt old and gummy, and the focus had a stiff spot in its travel. The second was slightly smoother once it was CLA'd, but nothing like a good Leica or Hexanon lens. It really spoiled my use of the lens.
 
Any idea what serial numbers to look for to tell if it's a "late production" lens?

The best way to tell is by looking at the rear of the lens. The re-design lens doesn't have any sunken screws around the rim of the cam.
 

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The type 2 40mm Noktons are definitely smoother and lighter to focus. The first type sometimes was uneven in its focus, with firmer and light focusing spots as you moved it. (It should be noted that some found that they loosened up with time and use and have been most satisfied although others like myself have noted they kept getting looser and looser until the front of the lens itself became loose.)

One important thing to know with the first version is that the focusing ring appeared to be too thin and it distorts ever so lightly and can cause resistance if pressure it applied incorrectly. So try to use the tab in a light left and right motion, if you press down on the tab or any other part of the focusing ring you will start to feel resistance in the focus. The example that I sent back when the lens was first released felt like you were putting the brakes on if you attempted to grip the focusing ring in any way or apply a downward pressure on the tab. The same thing with the second version did not have any effect. The redesign was swift and effective and I was impressed by Cosina's instant response to the problem. Every version 2 lens I have seen has had smooth and even focus, If you have a version 2 lens with rough or uneven focus then you may need to have it looked at.
 
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interesting photos

interesting photos

Do any other CV or M-mount lenses have screws in the cam area? I'd be curious when the cutover s/n or date was for the newer design.

The best way to tell is by looking at the rear of the lens. The re-design lens doesn't have any sunken screws around the rim of the cam.
 
The best way to tell is by looking at the rear of the lens. The re-design lens doesn't have any sunken screws around the rim of the cam.

Are you talking about the screws in the bayonet flange? It looks like there are screws in both photos. Is it that those in the earlier version are more deeply countersunk? Or am I missing the point?
 
Are you talking about the screws in the bayonet flange? It looks like there are screws in both photos. Is it that those in the earlier version are more deeply countersunk? Or am I missing the point?

No, ignore the silver mount and look at the black cam. On the type 1 you can clearly see a black screw there, the type 2 does not have any screws on its cam. I just did a quick re-do of the image for another thread.
 
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