Re: [Leica] Problem with M6 scratching film

["Gareth Jolly" <garethjolly@bigpond.com>]

I posted a similar message to LUG a month or so ago and have been discussing
the matter with Gary Colby who has had a similar problem.

Interestingly, the serial number of my M6 is 24329xx - very close to the
serial number you identified as the problem.

I am still in the process of testing the camera (delayed somewhat by other
time pressures).

My problem is precisely the same - no scratches on films from other cameras
with the film handled and processed under the same conditions; and scratches
showing up on a scan and if you angle the film to the light, but not on a
loupe.  I've theorised that this might mean that the scratches are dug
directly down into the film - i.e perpendicular to the film base.

The scratches on my film are not in one consistent place on the film.

While it has been suggested that the problem could be dust or grit in the
camera or film canister, I am confident that this is not the problem.
Otherwise, it would show up on my film taken at the same time with my Nikon.

In short, Gary and I have tried 3 things between us to solve the problem:

1.  Both of us have tried slowing the winding back of the film and
preventing the the film winder from spinning back uncontrolled, when the
film winder is released at the end of rewinding the film;

2.  Gary has swapped camera backs between his 2 M6s, which seems to have
solved the problem;

3.  The camera store at which I bought the camera has suggested that both M
and R bodies scratch film if the film is loaded with the tongue of the film
poking through the spindle (i.e the spindle onto which the film is wound)
and protruding out through the other side of the spindle.  I am in the
process of trying this to see if it works.  If it doesn't work, then I'm
going to try and get the M6 swapped (which might be difficult) or repaired
under warranty.

I haven't been encouraged by the M6 manual suggesting that loading the film
with the tongue protruding is fine.  Does anybody know if 3 is correct?

Gary has also discovered that some negative sleeves seem to leave fine
scratches on film.

Finally, some people have suggested that these scratches don't show up on
darkroom prints.  I haven't tested this yet.

Regards
Gareth Jolly



- -----Original Message-----
From: Mark E Davison <Mark_E_Davison@email.msn.com>
To: Leica User Group <leica-users@mejac.palo-alto.ca.us>
Date: Tuesday, April 06, 1999 5:24
Subject: [Leica] Problem with M6 scratching film


>I'm a Leica newbie and had a recent experience I thought I would share with
>the LUG.
>
>In trying to buy a new M6 body I ran into a batch of bodies which left two
>trails of scratch marks on the back of the film (the shiny side away from
>the lens). The scratch trails look as if someone had run two small abrasive
>pads down the length of the film, just inside of the film rails. On
>developed film you cannot see the scratches with a loupe, but they show up
>on scanned slides (Nikon LS2000, with and without ICE automatic defect
>correction turned on,) and you can see the scratches with the naked eye if
>you hold up the film so you can see the reflection of a light source (like
a
>small flashlight).
>
>I sacrificed a roll of unexposed film (Kodak royal gold 400) and determined
>the following:
>
>1. the scratching occurs when the film is transported in the M6. The same
>film goes through my OM4Ti with no scratches, so I don't think it is the
>film cassette.
>
>2. the film pressure plates on all 3 offending bodies were VERY abrasive:
if
>you lightly brushed the back of a piece of film across the plates, visible
>abrasion occurred on the film. No such abrasion occurs on my OM4Ti, or on a
>random M4 chosen for testing.
>
>The three bodies that scratched had serial numbers of the form 2433xxx.
>
>Glazer's Camera in Seattle was very understanding with me, and kept
swapping
>bodies until we found one that didn't scratch. We finally settled on a body
>with a serial number far away from 2433xxx.
>
>Surprisingly, every modern classic new M6 that we looked at has a somewhat
>abrasive film pressure plate, as shown by the film back scratch test, but
>not all of them leave scratches on the film in actual use.
>
>
>
>
>