I have a 4th generation non ASPH 35 Summicron that has gathred some dust on the lenses around the aperature. Would a make a BIG mistake by taking it apart and cleaning it myself? The reason why I ask it that I have done exacly this on a number of Nikkors, including lenses with internal focus.

$100 buys a lot of film...

/Fredrik Annell

-- Fredrik Annell (freann@mac.com), March 05, 2002

Answers

Fredrik:

It should be done professionally. If dust is the only problem, you might even get away with a bit less than $100.00. If you try it yourself, it might cost more than that to correct any problems you cause. It's a worthwhile expense.

-- Bob Fleischman (RFXMAIL@prodigy.net), March 05, 2002.

All lenses, however carefully you look after then will suffer some dust entry, here is Mr Putt's view:

"...It is impossible to manufacture a 100% fault-free product. And all and every Leica lens has dust within the lens elements. No Leica lens has a sealed vacuum part. So dust particles are part of the assembly and will be seen. When you put yourself in a darkened room and shine a point source through the lens, you may feel shocked by what you assume you see: a whirlstorm of dust that MUST degrade the image quality. Nothing is farther from the truth. The amount of dust you see, is in fact extremely slight and magnified in size by the optical cell. When I put a lens on the bench and a high powered intense light is shining through I see a Odense¹ cloud of dust particles. But it is harmless optically speaking and in reality much less intimidating than you dare to be afraid of. Again sometimes a lens has a higher amount of dust than another and here cosmetics start to operate. But is very difficult to make any objective observations in this respect..."

In some respects I have found zoom lenses with their zooming and 'sucking' action tend to pull in the dust more than primes.

-- Giles Poilu (giles@monpoilu.icom43.net), March 05, 2002.

The v.4 Summicron was assembled with thread-lock compound (a type of glue). Many people have taken them apart, only unintentionally ;>) If you have a lot of experience disassembling lenses, you might have a go at it. Be advised that Leica helicoids are much finer-pitched than Nikkors (use less grease to maintain the right feel, and hence perform equally in cold or hot temperatures), and coatings on internal elements are sometimes quite fragile. Replacement elements for Leica lenses are *staggeringly* expensive...kind of like if you tried to build a car from parts it'd cost 10x the sticker...so if you screw up, it will cost you a *lot* more than $100.

-- Jay (infinitydt@aol.com), March 05, 2002.