[Leica] Re: M6 film scratching

["Mark E Davison" <Mark_E_Davison@email.msn.com>]

I recently reported a problem with new M6 bodies scratching film. Here are
some details of my experiments which might help clarify things.

1. The scratches I witnessed were almost undoubtedly due to the abrasive
film pressure plate. This is because if you cleaned the plate with a cloth,
then conducted the scratch experiment (which consists of running unexposed
film through the camera, and opening up the back before rewinding, so you
can verify that scratches are being made) , you could see trails of debris
on the pressure plate at exactly the locations which were being scratched on
the
film--just inside the film rails. (The debris trails were easiest to see by
illuminating the pressure plate with sidelight from a flashlight. Hold the
flashlight so the light shines perpendicular to the direction the film moves
across the plate.)

2. I tried some experiments with the baseplate off, so I could advance film
with the pressure plate down or up. These experiments indicate that the
scratches get formed when you advance the film. Rewinding may add to the
scratches, but I didn't verify that. Slow rewinding will not avoid the
scratches.

3. The amazing thing is: no other camera I have looked at has such an
abrasive pressure plate as any recent M6. Some LUG participants may go into
a
state of denial over this, but I think it is definitely a defect Leica has
allowed to creep into their production.

4. Both of my current M6 bodies will intermittently scratch the back of
film. I attribute this to their pressure plates probably bearing more
lightly on the film. But their pressure plates are still quite abrasive.

5. In the end, I wonder if there is any easy way to polish the pressure
plates so they are smooth, without destroying the black finish.

To repeat: these scratches are quite visible with the naked eye, and they
are a real pain to clean up with Photoshop after scanning, because they are
really abrasions: many, many scratches close together.

These abrasions do not appear under a loupe looking straight down on the
negatives. I don't do darkroom processing, so cannot verify if the abrasions
cause problems in ordinary optical enlargments.

None of the other cameras I own (OM4Ti, Nikon 35Ti, M3) leaves this kind of
abrasions on film, only the M6's.