Help needed

[pixman]

Hi, I have just bought a Contessa LK :bang: on Ebay and everything is working fine. After running a roll through it, I found the pictures seemed overexposed. On looking into things further, I discvered that the rear lens element appears dirty. It looks like a window that hasn't been cleaned in a long time. I think this is why my pics look diffused. Some shots, taken without the sky in the picture, are quite acceptible. Am I right about the rear lens and if so, how hard is it for someone with limited experience to clean. Rod. :bang:

 

[Frank Granovski]

The whole picture looks diffused and over-exposed. I don't think this is a lens problem.

 

[bobofish]

I'll give you similar advice to the car mantra "Whatever's wrong with your car, change the oil. If your engine is hot, change your oil. If your tires are flat, change your oil. If your windows won't roll up, change your oil."

When all else fails, clean your lenses.

I do think it's a lens problem. Overexposure doesn't usually give a hazy look like that, it almost looks like a soft focus filter.

I don't know much about the contessas, but it looks very much like the effect you'd get if you left a lens sitting rear element up in a smoker's house for a couple years.

Blow all the dust off, with compressed air or a lens brush, and then use soft lens cloths to gently wipe off the grime. If that doesn't work, change the oil in your car.

By the way, I like the Zeiss lens cloths; they are CHEAP and quite acceptable. And no Frank, they're not made in Germany.

 

[Mike Kovacs]

Check the shutter - when you fire on the high speeds, are the blades moving quickly or is there some hesistation? There aren't any bellows so scratch that as a cause.

Otherwise, cleaning the lens is simple enough, as long as the crud isn't internal.

 

[pixman]

Thanks everyone. I will have another go at the rear of the lens. What would you recommend as a cleaning agent? I really like this camera and I would like to use it. I have played around with some of the pictures in Photofiltre and they can be made to look reasonably clear. Despite the haze, it is possible to see that the lens is really sharp. The meter works but I prefer to use the sunny 16 method. I will post some shots when I have sorted the problem. Rod.

 

[Mike Kovacs]

Personally - I use simple household ammonia applied with a dampened, lint free (Kimwipe) tissue, then wiped away with a second, dry lint free tissue. Doing a lot of camera repairs for my own collection, I think that people go crazy spending money on expensive lens cleaning products.

Blow the lens with air (not breath) first, clean lightly the first time, then as many rounds of fresh wet/dry tissues as necessary to do the job. Last bits of dust can be blown off or wiped with a clean microfibre cleaning cloth. Always use a light touch - pressing down hard or rubbing is not the way to do it - let the tissue and liquid do the job.

If there is haze on the lens (normally an internal problem), substitute 50/50 household ammonia and household hydrogen peroxide.

Same household ammonia technique for aluminized first surface mirrors - but even more care is warranted. They are more fragile than lenses, but not so fragile that they can't be cleaned with care and a light touch.

 

[pixman]

Thanks Mike, I have cleaned the external surface of the lens but no improvement. I guess the crud is internal.I am reasonably handy so I wonder if I can strip the lens and clean it myself. A lens spanner may be a problem though. Rod.

 

[drmatthes]

Sounds like fungus to me. Any ideas on that, guys? Or is it blade oil spinoff?

That's the problem with the "near mint" stuff from the 'bay in "perfect working order". Or was it "sold as is" or "I don't know much about this camera which was owned by my grandpa who always kept his belongings tidy until he passed away ten minutes ago"?
I have run into this trap twice (or more) myself.

Anyway:

If it is fungus, I have been told that polishing the lens element might do the job, but heavy polishing removes coating and can even change focal length. I have an ICA plate folder. A friend of mine has done polishing to the lens which is no problem with uncoated types that will focus in a ground glass. Works fine now. Contessa LK might need focus readjustment/calibration on an optical bank/collimator afterwards...

The Tessar 2.8/45 is a great lens that has been put in front of many ZI models in the nineteenfifties, most of them still selling for "an apple and an egg", as we say in Germany, so it might be wise to get another one (that's what I did with my sticky Minox 35 and my prehistoric Dacora when prices dropped due to the digital boom a couple of years ago - I did it twice because wise guys played tricks on me on the 'bay, see above...).

If it is blade grease, things might be easier with the methods Mike has described. But as in the Tessar the elements may well be glued together (I don't know the proper expression for this in English nor the exact ZI lens construction), the task may well be half way between tricky and impossible.

Good luck, give us an idea,

enjoy (?)!

Jesko

 

[pixman]

Thanks everyone. I think I will have to get another.