Oil on aperture blades

[mike_j]

My newly aquired Jupiter 8 has a little oil on the apterture blades. I'm a bit reluctant to strip it down as it's too easy to damage the finish of lens retaining rings etc but I was wondering - does it matter?

The aperture changes smootly over the full range, and it's not like a shutter or auto aperture camera where a slight extra friction upsets the action.

If I do strip it down I'll see if I can put a little voightlander type focussing knob on the focussing ring, I do find that it's too esay to change the aperture when focussing with these lenses as they have no click stops.

 

[fidget]

hi, a couple of my lenses now have oil on the aperture blades, including my J8, after I serviced them and used the wrong grease (which separated). So far it hasn't been a problem. They are easy to strip, so I will eventually go in and clean it all off. I saw a thread here which suggested that the now shiny blades could reflect back onto the film in some extreme conditions, so there could be a good reason to clean it off.

 

[Valkir1987]

I have a J-9 with an aperture which is somewhat drained in oil. It causes problems in many light conditions. I'm about to let it clean by a repair shop somewhere. Although the J9 is not the J8 dirty apertures can cause problems. Oil can become grease, and grease can become stiff after some years.

 

[b1bmsgt]

If you get the blades too clean and everything moves too freely, then the aperture can change on it's own when you focus (if there are no click stops as in, apparently, most FSU lenses). Some sites actually reccommend a little oil on the blades to keep everything in place.

Just my .02 worth...

Russ 😀

 

[oscroft]

My J-9 has got some oil on the blades, but I've had no problems and it performs beautifully, so I'm not going to tamper with it.

 

[wolves3012]

I have two Jupiter 8s, one of which has a lot of oil on the blades and the other none at all. When I get the chance I'll try them both to see if I can spot any difference in flare etc....I'm curious about this too! I can see the logic that oil can cause reflections, so we'll see if reality bears that out.

 

[raftman]

Sometimes, at least from my observation, the aperture blades can wear to such an extent that the areas surrounding where the blades overlap can become "shiny" and can at first glance look like oil on the blades. This was the case with my Kodak 35RF... the camera did have a whole host of problems, but flare didn't seem to be one of them.

I've an I-61 L/D that seems to have a bit of oil on the blades, and it's never been a problem either.

 

[John Robertson]

My jupiter 12 has had oil on its blades for 25 years, its never got any worse and has had no effect on performance!

 

[steamer]

I have a Zeiss Jena 8.5cm sonnar f2, which the J-9 is modeled on I believe. The aperture blades are very greasy and in bright light or any kind of backlighting the flare is ginormous, it blows out the middle of whatever I'm aiming at. My New Year's resolution is to get it fixed.