M6/later cameras have more light-tight shutters?

Just checking my cameras and noticed the following: The M6 has a thin

plastic baffle in the shutter/film gate that is not present in my M4-2

(see illustration).

 

For those who haven't experienced it, with some M rangefinders, it's

possible to get fogged bands on frames if bright light (sun) shines

into the open lens mount while changing lenses. Seems like this was

added to the design at some point as a fix.

 

Since I 'grew up' with the M4-2, I developed the habit early of turning

away from the sun when switching lenses after getting a few fog marks -

and still do it with the M6. So I can't speak to how much improvement

to light-tightness the baffle actually provides.

 

Perhaps just a trivia point, but it might be interesting for those of

you with M3/2/4 or M4-P's to check next time it's convenient to see if

this was added with the M6, or just one of those items left out of the

M4-2 by Leitz/Canada for cost reasons.

 

Ever gotten edge fogging from a lens change with an M6/ttl/7/P?<div></div>

Andy, nice to hear from you. I would say you are right. Checking an MP, it has a little strip that does not move as the shutter is being wound. My M3 has no such strip. The rest have film in them--it's easier to check when there's no film, so I can work the shutter. I will check them as soon as they are empty. I believe I see the strip in my M6TTL, but it's hard to make out without moving the shutter.

andy, good info. thanks.

i will keep an eye on whenever i change lenses. i use m3 and m6.

once i empty the rolls i will check it out.

In my M4 (and in the M4P I used to have)if I put the shutter on "Bulb" and look from the back, down into that slot where the shutter edges ride, I can see a fuzzy black strip, like the furry side of velcro. That was probably replaced by the plastic strip. I couldn't say whether the new design is better or just cost Leica less to make. I do recall Sherry saying she replaces that fuzzy strip on the older ones so it probably wears out or deteriorates.

Ben: Yes, now that you mention it, my M4-2 has fuzzy velvet lining the front inside surface of the channel. No doubt it has been worn down enough after 26 years of shutter rubbing (as Sherry says), that it's leaking a bit now.

 

I even got fogging of this type once or twice with a 21 Super-angulon mounted - the superwide, super-close-to-the-film lens projected an image of the overhead sun at such a steep angle that it leaked through the channel "U" just carrying the combo around sans lens cap (too small an aperture to burn shutter curtains, though).

DAG calls these light shields. The older style may become ineffective. Both my M`6 required replacement, twenty years old but less than 50 rolls each. My M3 light shield was replaced because of similar fogging a year or so ago.

 

When they go, film will fogg even without changing lenses.

An update: "tested" my M6 by loading HP5, taking off the lens, and holding the camera in the sunlight as it might hang while changing lenses - for about 15-20 seconds.

 

No fogging even on ISO 400, whereas my M4-2 with worn (probably) velvet often fogged ISO 50 Velvia with this amount of exposure.

Hhm. WWII technology obviously.<div></div>

Anybody have an idea as to why this isn't a problem with M2 and M3 bodies made way back in the 1950's and 1960's? All my bodies currently have film in them but I don't recall noticing any fuzzy or plastic strip there. None of the 4 bodies ever leaked light. Hell, they can't even MEASURE light!