40mm Nokton very stiff focus - fixable?

[kevin m]

I just purchased a used 40mm Nokton SC and I'm quite pleased with the image quality, but the focus is so stiff and jerky that it really spoils the use of the lens. It's so bad, in fact, that I plan to return the lens. In addition to that, the front of the lens has a bit of a wobble in it, even though the lens looks like new.

I evidently have the 'early' version of this lens with the screws visible on the focusing cam, so my question is, is this lens "fixable?" That is, will a trip to DAG or Sherry Krauter make it focus smoothly and fix the wobble? And if not, does the newer version of this lens focus smoothly?

Thanks! 🙂

 

[kevin m]

Thanks, Roland, but I searched the archives and came up with nothing. If I search "40mm wobble" now, the only hits are your post and mine. 😕

 

[kevin m]

So no one else who owns this lens has had it serviced to fix the stiff focusing? 😕

I can focus my 50 Summilux or 40 Rokkor with a very light touch, but this thing is damn near unuseable as it is, despite its fine imaging quality.

 

[kevin m]

FWIW, I called DAG today and he said he's worked on the 'version I' Nokton and it requires a bit of thread lapping to smooth out the focus.

Since he's evidently worked on a few, has anyone here had the work done, and were you pleased with the results?

 

[kevin m]

So everyone knows about this problem, but no one has bothered to have it fixed? 😕

Very well, then. My lens is off to DAG. I'll let you know how it turns out.

 

[Flyfisher Tom]

Not suggesting that you do this yourself, but reg. the focus on the 35/1.7:

- took off the lens mount.
- underneath I found three black screws. When you unscrew them you can take off the entire back barrel of the lens, and the focus helical is accessible for lube.
- when you put it back together, the black screws also align the helicoid with the RF setting, so you have to try out on your camera until you get infinity focus right.

I had to do this because there were some drops of fluid on the internal elements of the lens that I bought used (still don't understand how they got there ....)

Roland.

Roland,

What would you recommend as a lube? I've heard that white lithium disc caliper grease is a good possibility.

Anyone know for certain what DAG or Krauter use for lube?

 

[Xmas]

Hi

Several people have posted 40mm heavy focus problems, there are several threaded assemblies and the friction builds between them. Using a lighter lube than the manufacturer used will help, an abrasive seems exteme. Some of the practical people may relube it for you, instead of a professional.

I normally use a trace of PTFE liquid as I dont mind feeling slack and slop in the focus, which might annoy others, not got a 40mm myself though.

Noel

 

[Didier]

I just purchased a used 40mm Nokton SC and I'm quite pleased with the image quality, but the focus is so stiff and jerky that it really spoils the use of the lens.

Mine was stiff, too. Just use it, use it, use it. And when you don't use it and watch TV for example, focus it up and down, as a kind of meditative activity. The lens will get smooth, promised.
Didier

 

[kevin m]

Thanks, Didier, since I missed the post office this morning, I'll give it a try!

 

[mtscherning]

Mine was stiff, too. Just use it, use it, use it. And when you don't use it and watch TV for example, focus it up and down, as a kind of meditative activity. The lens will get smooth, promised.
Didier

I guess this'll be my way to solve this thing too, in my opinion though - rather too stiff than too loose. Won't you risk getting it too soft over longer time by kicking off by this?

 

[irq506]

Yeah I know about that stiffness in the 40 f1.4 Nokton, its completely fixable. I work in a tech shop and had it open cleaned and relubed with better lubrication, the cleaning part of it is crucial, basically its adviseable for the components to be completely devoid of lube and then rubbed down with a very fine grade brass haired wire brush and then polished with cutting compound, lubricated and re-assembled. Of course, sitting on the couch in the warmth of your abode and your hands and repeatedly throwing the focus will help smoothen the throw.

 

[5nap5hot]

Are they poorly lubed from the factory? I have a brand new one and notice the stiffness as well.

 

[BillBingham2]

Mine was stiff too to be happy with, I tried for several months. The smoothness of my 35 ‘cron and CV 35/1.7 was just too much better. So I sent it back to Stephen Gandy and got it fixed under warrantee. I just got my 40 back from DAG having it tweaked to bring up the 35mm frame lines on my M6/M4-P. DAG is great with lenses, I have two older ones in with him now. DAGs prices are reasonable and his quality second to none. Send it along, it’s a lens that should be focused with a ring-finger, nothing more.

B2 (;->

 

[kevin m]

My Nokton is "new" too and the focusing is simply inexcusable. It's not only stiff, it feels cheap, too. Like the helicals are binding as they move. The image quality, as I said before, is very nice, but VC pisses me off with their hit or miss attitude to quality control. My two Summiluxes and my Hexanons focus smooth as butter with light finger pressure and feel like a million bucks doing it. Heck, I have 50-year old Canon that does, too. That's the standard VC needs to match.

DAG says he can fix it, and I'm going to give him a shot. Much as I'd love to take the lens apart and play with it, I have a new scanner I need to learn how to use properly. I'm confident that will yield more photographic benefit than my amateur lens technician attempts. 😀

 

[BillBingham2]

DAG is much faster than warrantee, but cost more (if you got it from Stephen). I've got a lot of other CV lenses and this was the first I've had any issues with. Come to think of it, it's the first I've hear of any regular issues with. You say you got it new, I wonder if it was new to you, but sat on the shelf for a while. I've never heard of issues with the 40 other than those who got the first batch or so.

Just a thought.

B2 (;->

 

[gullevek]

Shipments to america have bad quality so people can rant in forums about it? My guess so, or well, I just have to Cosina lenses (12mm ultra wide heliar and the 40mm nokton mc) and I have no issues at all. Their build quality is superb. Top notch.

[I live in Japan, just to add oil to the fire]

 

[5nap5hot]

Well... I wouldn't say mine is that bad. It focuses precisely. It just seems to require a little more effort than focusing a SLR lens. The CV 40/1.4 lens is nowhere near as stiff as the Jupiter 12 I have... THAT is stiff!

I don't have much experience with rangefinders...so I don't know what is "normal"

 

[irq506]

Are they poorly lubed from the factory? I have a brand new one and notice the stiffness as well.

There's lube and there's lube...
Im assuming that the lubricant in the CV lenses is a generic oil/wax based compound, probably because its cheaper for them to use, also the fact that they are less expensive lenses, they are probably stocked in warehouses and shipped in crates, where its cold, and some lubricants can emulsify. Other lubricants with slightly different ingredients will have differing charateristics. Some older non silicon lubricants, some with a low soft "wax" ratio work extremely well, and perform beautifully if warmed up in your pocket for about 15 minutes before use. Silicon lubricants can actually damage some metals.

Also, the machining of the individual brass components (even the choice of the metal density and ratio of copper to zinc can create a hard or soft brass), I can only assume is done with somewhat less care then is done with a Leitz lens.
Thats why we will actually burnish the brass components of these lenses before testing and reassebly.

I do agree with the apparent lack of quality control consistency from CV lenses and shutter mechanisms, Ive seen quite a level of fluctuation in their lens quality especially. However lets not compare CV to Leitz anymore, like with like, they are almost completely different animals.

 

[kully]

I'll to add to those who have said use has freed up their 40/1.4 focussing. My lens did move like a buffalo carcass when it was new - but over the summer it's become lovely smooth - I focus it with just one finger crocked in the tab thing.

 

[sleepyhead]

I have a 40mm 1.4, single-coated version, bought second hand. Focus stiffness and smoothness are perfect - so they're not all bad.