Nikkor S.C. 50/f1.4 - stiff aperture ring?

[Waterman100]

I have a Nikkor S.C. 50/f1.4 lens, black and chrome barrel version, that came with a SP. The lens's aperture ring appears to me to be very stiff -- it is almost impossble to turn the ring without also moving the focus ring. So I always need to first set the f-stop before focusing.

Does your lens have the same problem? Do you think it needs to go to Pete Smith for some CLA (I presume he works equally well on lenses...)?

Many thanks for the help.

 

[Tom A]

It could be simply lack of use. the grease can harden in the helicoil. Try exercising it and see if it loosens up. A heliocil lube job is not a big deal. Just about any competent technician can do it - and with some care, you can probably do it yourself. Check with Btian Sweeney too - he knows how to take lenses apart.

 

[NIKON KIU]

I had a 1.4 with the same issue, after Pete cleaned it up it was still stiff but not as bad as it used to be.
Like Tom said, it is simply because of lack of use.
The more you use it after the CLA, the better it gets. 😎

Kiu

 

[jonmanjiro]

> I have a Nikkor S.C. 50/f2 lens

Now that's a very very rare lens 😉 The normal 50/2 is a six element lens so has the designation "H". If your lens does indeed have the designation "S" indicating that it has seven elements, then its a super rare prototype collectors item 😀

Back to the problem at hand! Its a very simple fix. The aperture adjustment mechanism just needs a clean and lube. Really simple to do on these internal mount 50s as there's no focus helicoid in there to complicate things. Any good repair guy should be able to do it.

 

[Highway 61]

This is a 30 minutes DIY job using lighter fluid, an old toothbrush, a tweezer, one 0.5mm screwdriver and some white lithium grease, plus some nail gloss to secure the aperture ring set screws (those set screws' torque force adjusts the aperture ring stiffiness by itself, so they must not be screwed in totally unless you are going to lock the aperture ring : you have to find the proper position of each set screw so that your aperture ring is firm enough with no play but not stiff and not grinding, then you secure the screws heads with a tiny dab of nail gloss to prevent them from turning by themselves when you are outside using the lens ; before removing the set screws you can notice that Nikon applied some brown varnish on them at the factory, just for this reason).

First thing to begin that lens service is to simply unscrew the thick black washer at the rear of the lens by gripping it with a rubber pad or a leather glove, then you pull the optics module out of the main barrel (don't lose the infinity collimation brass spacer), and you have access to the aperture ring set screws. Once they are off you can pull the aperture ring towards the rear of the module and clean everything in lighter fluid (sometimes once it's done you have to go to the kitchen and re-clean the parts with hot tap water and dishwashing soap - hence the toothbrush. Of course don't forget to rinse and then carefully dry up parts that have been under tap water with your hair dryer before you reassemble.

Worse case, there are sticky oil deposits inside the aperture mechanism and/or on the aperture blades, if it's the case then you are in for a total stripdown of the lens, a bit more complicated if you never ever worked on such toys, but nothing that requires either fancy tools or special machinist skills.

Brian Sweeney must have detailed close-up pics of the process.

 

[Waterman100]

> I have a Nikkor S.C. 50/f2 lens

Now that's a very very rare lens 😉 The normal 50/2 is a six element lens so has the designation "H". If your lens does indeed have the designation "S" indicating that it has seven elements, then its a super rare prototype collectors item 😀

Oops, you got me there. I made a mistake. The lens was not a S.C. 50/f2, but a S.C. 50/f1.4; so sadly, no hidden treasure here but a great lens nonetheless.

 

[Sonnar Brian]

Could be grease under the aperture ring, could be the mechanism. On mine, it was the click-stop mechanism.

It has been a while, but I had one that was like this: the aperture stop mechanism uses a metal tab to catch the grooves for the click-stops, and it was bent and hung up. Unscrewed the lens in front of the aperture mechanism, and could see the bent metal.

if you are comfortable with disassembling a lens, the Nikkor 5cm/1.4 is easy. Just unscrew it. The optics module is held in by a retaining screw at the back, the optics module unscrews like a Summicron. If not comfortable, best to send it in for a CLA.