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Helios 44: Oily Aperture Inevitable?
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PostPosted: Fri Apr 01, 2022 6:36 pm    Post subject: Helios 44: Oily Aperture Inevitable? Reply with quote
Has anybody had luck with servicing a Helios 44 lens and not had the aperture develop oil again?

I had a friend travel to Eastern Europe and I asked him to get me some lenses. He bought a Helios 44 from a camera shop that appeared to be serviced (CLA). Lens aperture was completely clean of oil. Now a few years later it is back to being oily like the majority of the Helios lenses.

I have a Helios I would like to service, but I won't waste my time if the oil just keeps coming back no matter what. Anybody that had one with an oily aperture manage to get it clean and keep it clean for years?


PostPosted: Fri Apr 01, 2022 8:02 pm    Post subject: Reply with quote
I can't comment on the Helios 44 lens specifically, but I do know that some lenses are particularly more prone than others to developing (and/or re-developing) oily apertures.

Potential solutions are:

1) Live with stiffer focusing and use a thicker grease. All greases are designed to release oil under pressure & sheer stresses, that's what greases are for, and all will eventually spontaneously release some oil, but thicker ones are less likely to do so and will take longer to do so.
2) Live with some possible play in the helicoid and/or uneven dampening feel and use less grease.
3) Live with some guaranteed play in the helicoid and only use a dry lubricant (like molybdenum disulfide or micronised teflon)
4) Use an anti-diffusion compound / oil barrier, like Nyebar. Minolta used an Emralon anti-diffusion compound in some of their lenses, but that no longer exists under that formulation. Nyebar from nye lubricants (https://www.nyelubricants.com/nyebar) is a modern equivalent, but I have yet to find an outlet/supplier for individual consumers like us... Sad


PostPosted: Sat Apr 02, 2022 6:32 am    Post subject: Reply with quote
RokkorDoctor wrote:

Potential solutions are:

. . .


Helpful information. Thank you.


PostPosted: Mon Apr 04, 2022 8:07 pm    Post subject: Reply with quote
If I can get my hands on nyebar, then where would you apply it?

The other options are less desirable. I don't like stiff grease on m42 lenses as without a bayonet they can just unscrew if the grease is too thick. As for play in the helicoid I would rather live with an oily aperture over helicoid sloppiness.


PostPosted: Tue Apr 05, 2022 8:45 am    Post subject: Reply with quote
cbass wrote:
If I can get my hands on nyebar, then where would you apply it?

The other options are less desirable. I don't like stiff grease on m42 lenses as without a bayonet they can just unscrew if the grease is too thick. As for play in the helicoid I would rather live with an oily aperture over helicoid sloppiness.


Very hard to advise without seeing the lens assembly, as the most appropriate place to apply it would vary from lens to lens. Not all lenses are suitable to have an anti-diffusion barrier like Nyebar applied, depending on the construction.

Neyebar would be applied somewhere on the surface of the inner optical block mounting cylinder, somewhere between the helicoid and the aperture assembly. That is, it should be applied somewhere such that any oil separating out of the helicoid grease and migrating along the surface of the block, would need to pass the Neyebar barrier to get to the aperture. It only stops diffusion, it would not stop any oil evaporating & condensing on the aperture, e.g. in very hot conditions.

As an example, below is page 4 from the service manual of the MINOLTA MC ROKKOR 24mm f/2.8 (excuse the poor lighting; I took a quick snap near the window next to my computer Wink )

Fig. 4 shows a partial cut-out of the rear part of the floating-focus cylinder, (the cylinder without a part no. shown at the top of the page in fig. 3.) It is oriented such that light would be entering the lens from the left, i.e. in figure 4. the optical axis is oriented from left to right, and only the top corner of the rear of the floating focus cylinder is shown. The tread shown at the bottom-right of fig. 4 is where the rear optical cell will screw in. The chamfered recess in the middle of fig. 4 is the clearance for the aperture assembly. This figure shows where the Emralon 325 anti-diffusion compound is to be applied. As you see, the anti-diffusion compound is applied fully surrounding the aperture assembly, but not on or in the aperture assembly itself.

(Fig. 5 shows the setting and locking tools required for setting and temporarily locking the floating focus space during collimation).

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