Re: [Leica] problem

[Kip Babington <cbabing3@swbell.net>]

I had occasion to check the light tightness of my M6 shutter recently, because I
was checking an obviously leaky IIIc and decided just to see how the M6 fared
under the same circumstances.  I used a bright spotlight in my darkroom, with a
rest that put the camera body with the lens mount facing the light.  My meter said
it was about 4 stops down from sunny 16.  The film (Delta 400, which I normally
rate @ 250 and develop in PMK pyro) showed fogging at both 20 and 40 seconds on
the first curtain (i.e., with the shutter cocked) just barely perceptible fogging
at 20 seconds on the second curtain and slight fogging at 40 seconds on the second
curtain (but not as bad as at 20 seconds on the first curtain.)  The fogging
begins about a millimeter or two from what would be the top of the image (bottom
of the camera) and does not have an absolutely crisp top edge, so I'd guess that
it's not coming through the curtain material itself but around the edge and being
reflected from the channel in which the shutter moves.  The fogging fades away
toward the center of the frame, and at its widest the band is about 3mm wide.
There is a narrower and less dense band that appeared at the bottom of the frame
on the first curtain (very slight at 20 seconds, somewhat worse at 40), but not on
the second curtain.

I was surprised to see any fogging at all (although this was much better than the
IIIc I was checking out) and even more surprised to see a difference between the
first and second shutter curtains.  I don't know if my camera is typical, but this
is an easy test to perform with the last few frames on a roll if anyone is curious
about their own body.  I'm certainly more careful about changing lenses now, and
if I know I'm going to change after a shot I try to remember not to wind the film
first.

I'd be interested to know if any of the rest of you have had similar (or
different) experiences?

Cheers,
Kip

John Collier wrote:

> In the M manuals it warns against changing lenses in direct sunlight. It
> recommends, and I have always successfully followed, that you shade the
> camera with your body. The light trap where the shutter curtains meet is not
> absolutely light tight and under direct sunlight with no lens it will leak.
>
> John Collier
>
> > From: "Tofu" <topher@netvigator.com>
> >
> > Anyway, whenever i change the lenses on my m6, i've always had to be careful
> > not to do it in direct sunlight, or i get some 'additional exposure' on the
> > frame currently underneath the lens.....i kinda thought this was just a
> > hazard that came with cloth shutters, but after ruining some nice shots, i'm
> > really starting to get annoyed (at myself!). Is this actually just from
> > cloth shutters, or is my shutter coming apart? The marks are quite large,
> > though not very severe, so i don't think it's just little pinholes....and it
> > definately occurs only when i change a lens...
> > any advice? TIA...........
> > tofu!
> > anyone ever used the nocti for infrared?
> >