Re: [Leica] Veiling Flare in an M4-P

[Bert Otten <e.otten@med.rug.nl>]

As you can see in the archive, there were 5 reactions to my question about
veiling flare in the M4-P.

Thanks very much indeed.

Some said they had exactly the same flare with other lenses. That suggested

to me that the flaring light may not come through the lens but from
somewhere else.

That's when I found the solution to the problem.

1)    I put the lens (35/2)  with frontcap on the M4-P

2)    I opened the shutter with the backdoor up and the bottomplate in
place

3)    I placed a strong lamp under the camera

4)    I looked into the camera and found a lot of lightleakage between the
    flange of the lens and the mount on the camera. Especially bright were
the two screwhole rims in the lensflange, that were visible left and right
at the bottom of the mount where the mount has no claws

That explains the fogging pattern: If you draw a line from the
screws to the metal rim in front (lensside) of the shutter, it hits the
filmplane
about 2 mm above the lower imageborder. That is why the lower strip has
no fogging.

At a nearby Leica dealer I repeated the same procedure on another M4-P:
same effect

Then I put the lens on an M6: no leakage.

Possible explanations of the absence of leaking in the M6:

1)    the light baffle Leica has introduced just behind the mount in the
camera
    covers the leakage
2)    the springs in the mount of the M6 are a bit tighter, pulling the
lens closer to the mount


It is very unlikely that the front plate of the mount on the M4-P is
slightly warped, since the
other M4-P shows exactly the same.

It may be that the flange of the lens is slightly warped, although I can
not see any damage,
like a slightly bent claw of the flange. To inspect the lens, I've sent the
lens back to
the Dutch Leica importer, Odin. I'll keep you posted about their opinion
and possible solution.

It may well be that Leica knows about this problem and therefore introduced
the baffle in the M6.

However, since M bodies without a baffle are used a lot in the world, I
would like to
see a solution, and a better one than cutting a plastic baffle myself and
sort of fasten it
behind the mount (although if no solution comes up, that's probably what
I'll do to be able
to shoot pictures, because that's where I want to put time in)

Bert