Oily blades

[Fotal]

Someone made a comment (sorry, don't remember who) that oily blades can be bad in cold weather as they might break.

Are there any other reasons that I should consider a cleaning of the Jupiter-9 I just picked up?

[themoleman342]

Usually it's not an issue with preset lenses like the jupiter 9. In auto lenses the blades have to move quickly so if they are 'gummy' then they simply may not close. In cold weather the oil will thicken, so you have to be careful of that...as long as you turn the aperture slowly there shouldn't be any hang-up. If there is, never ever ever force it.

Besides that fact, the jupiter 9 is, or so I've heard, incredibly difficult to reassemble correctly. Many of the lemons on the market are due to people taking them apart and not being able to get them quite right again. This is not to say anything about your ability in the matter...just making you aware of the fact. Attila, I know, is of the camp that you NEVER disassemble a lens that doesn't absolutely need it.

Hope that helps in some regard.
~Marc

[Fotal]

Thanks Marc!

I can imagine that some lenses needs very special care when put together again after a dismantling. I'm thinking that there must be some factory service instructions for all the serivice shops?

Anyway, I'll leave it for now. The J-9 is otherwise in a very good shape but I have no adapter for it yet to try it out on the camera.

[LucisPictor]

I have taken several lenses apart and tried to re-assemble them.
With some it was pretty easy. Other lenses seem to have a kind of "recursive" design: you only get the inner ring fixed if the outer ring is already at its place, but this outer ring only goes there if the inner ring is fixed.
Don't laugh, this happens.

[Fotal]

[rick_oleson]

The Jupiter-9's reputation for being difficult to reassemble, I think, comes mainly from the focus helical system of the Leica rangefinder version of the lens. In that one, if you separate the focus helical and the rangefinder cam, your chances of getting it back together right are almost zero. Getting to the diaphragm, though, is not so hard, and the focus system isn't as bad in other versions of the lens... though the focus helical of any SLR lens tends to have a sort of "Catch-22" feel to it during reassembly.

Oil on the blades of an auto-diaphragm lens is a disabling problem, but on a preset or rangefinder lens you don't need to worry until the ring begins to feel stiff. When you get to that point, don't force it because you can damage the blades.

[Flor27]

[rick_oleson]

OUCH! how hard did you push on the aperture ring?

[Attila]

In similar cases I can't fixed my Steinheil Culminar 85mm f2.8 even if I spent hours with that,if any blade damaged minimally it not works any more.

[Flor27]

[hacksawbob]

you ca get to the rear of the aperture quite easily the front assembly screws out from the rear. you could treat this with lighter fluid and q tip, then reassemble use for a few more months then repeat each time reducing the amount of oil on the blades. as you use the lens the oil will transfer from front to back and gradualy you will reduce the ammount of oil on the blades. Here is my most recent J9 acquisition an single coated 74 version,
Click here to see on Ebay

[Flor27]

Actually my problem is to put the blades back in the lens. I guess I have to dismantle it more than what I've done to extract the broken set...

[rick_oleson]

I wonder if they were already damaged before you got it... I've never seen them that fragile, it takes some force to shear the pins off the ends.

[Fotal]

Flor, that looks nasty.
Good luck with the reassembly project!

[Attila]

You can't make this damages on a good working lens even if it was cold! I have and have many pre-set lens. They are not too sensitive pieces.In my opinion this lens was cleaned and wrongly rebuild. You did turn aperture ring on an already damaged lens!!