Re: [Leica] Dust In The Lenses?

[Christer Almqvist <christer@almqvist.net>]

>    My R100 apo and 80-200 f/4 have many dust and some  scratch
>inside. Are anyone's lenses the same as mine? Does it affect the
>picture quality? Any input would be appreciated.   TU+

I have had the same problem. Yes, it affects picture quality.

One of my problem lenses was my Focotar enlarger lens and here it was quite
easy to to see the effect. I had bought the enlarger second hand and before
I bought it I had compared the lens to my previous lens by making test
enlargements from the same negative. A couple of months later I thought
the prints made with the new Focotar did not come out as 'clear' as they
used to so I redid the test prints and compared the new ones with the ones
I had done before I bought the lens. I could see the difference with my
bare eyes. Looking for the cause I then discovered specks of black paint
inside the lens but only on the lens surfaces next to the aperture. I
concluded that the lens had been left unused for a good many years before I
bought it and my using it and opening up and closing down the aperture
rubbed off paint particles that then landed on the inner lens surface.
These specks are quite difficult to see and the best way to see them is to
put the lens on a light table and look at the inside surfaces witha loupe
as the loupe helps you to focus on inner surfaces rather than outer. I had
about two dozen specks on one surface and half a dozen on the other.

I had the lens cleaned by Leica (costs about $ 100) and now it is as god as
new. I then looked at my other lenses and also found that the 35 mm
Summicron had the same problem. I then went to an independent repair shop
and had it cleaned. They said it would be $ 50, but  when they saw the
Summicron they said $ 100 because ' on Summicrons it is so difficult to put
the aperture blades back in and we have to take them apart and clean them
if you want to make sure the problem does not reappear again, and very
quickly'. They needed two days for the repair while Leica need a few weeks.
The quality improvement  resulting from the cleaning was real, I had made a
few test shots before I had the lens cleaned, and then photograped the same
situation with a clean lens and the difference on the enlargements was
quite clear, although not scientifically proven