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Oily blades
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PostPosted: Tue Mar 18, 2008 7:45 pm    Post subject: Oily blades Reply with quote

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?


PostPosted: Tue Mar 18, 2008 9:42 pm    Post subject: Reply with quote

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


Last edited by themoleman342 on Fri Mar 21, 2008 2:40 am; edited 1 time in total


PostPosted: Wed Mar 19, 2008 3:58 am    Post subject: Reply with quote

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.


PostPosted: Wed Mar 19, 2008 9:35 am    Post subject: Reply with quote

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. Shocked Question Question Question
Don't laugh, this happens. Confused


PostPosted: Wed Mar 19, 2008 9:53 am    Post subject: Reply with quote

LucisPictor wrote:
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. Shocked Question Question Question
Don't laugh, this happens. Confused


sounds like you need a special Star Trek tool to handle these situations Laughing


PostPosted: Wed Mar 19, 2008 11:30 am    Post subject: Reply with quote

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.


PostPosted: Thu Mar 20, 2008 2:25 pm    Post subject: Re: Oily blades Reply with quote

Fotal wrote:
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?


That could be me, as I've broken some J-9 aperture blades while trying my freshly unpackaged and cold lens Crying or Very sad

A russian eBay seller sold me - on my request ! - a complete blades set, and now I have to figure out how can I fit them inside the J9...







PostPosted: Thu Mar 20, 2008 4:05 pm    Post subject: Reply with quote

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


PostPosted: Thu Mar 20, 2008 4:17 pm    Post subject: Reply with quote

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.


PostPosted: Thu Mar 20, 2008 6:03 pm    Post subject: Reply with quote

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

Not hard at all ! In fact, aperture ring was OK to turn but as the blades were sticky each other and are so thin and fragile, ...


PostPosted: Thu Mar 20, 2008 7:14 pm    Post subject: Reply with quote

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


PostPosted: Thu Mar 20, 2008 9:48 pm    Post subject: Reply with quote

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...


PostPosted: Thu Mar 20, 2008 11:32 pm    Post subject: Reply with quote

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.


PostPosted: Fri Mar 21, 2008 12:14 am    Post subject: Reply with quote

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


PostPosted: Fri Mar 21, 2008 12:22 am    Post subject: Reply with quote

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!!