Leica M 1/1000 uneven shutter issues

[ItsReallyDarren]

I've been noticing a problem when I shoot my M3 at high speeds such as 1/500 or 1/1000. The problem is more noticeable at 1/1000 where the left side of the frame is unevenly exposed. The problem is most noticeable with evenly lit exposures or with anything that has the sky in it.

Is this a common issue with M shutters at higher speeds? It was recently CLA'd by Youxin. Is this just an inherent problem with these shutters with the best remedy to use these speeds as little as possible or does this need an adjustment?

Take a close look on the left side of the frame, about 1/8 of the frame is slightly darker than the rest of the frame. These shots were taken on the 1/1000 speed.



The effect is more noticeable on the bottom left side. The brightness of the road shifts from darker to brighter about where the two lines are. The wall to the left of the palm tree shadow is also darker than the rest of the wall. Which was painted white in bright sunlight on a cloudless day.

 

[Roger Hicks]

Yes, it's a problem. Exposure should be even. Send it back.

Cheers,

R.

 

[planar]

Hi Darren,

I had the same problem with my M7. It turned out that when the shutter curtains are bouncing back a bit as they finishing their horizontal traveling. At lower shutter speed, that isn't a problem because they were sufficient time to "even out" the difference in exposure. However, there would not be enough time to compensate that if the time was short. So, just send the camera to your service agent and tell them the "bouncing curtain problem". Cheers,

 

[Erik van Straten]

It is a very common problem, known as shutter tapering. Both curtains have their own tension wich must be adjusted properly. A compentent repairman can do the adjustment in a few minutes.

Erik.

 

[marduk]

True. 1/1000 is often out of alignment. During a CLA once the specialist has got the exposure right (within acceptable limits - as I was told by a nice Leica specialist here in Kiev, Leica tolerance of 20% at 1/1000sec is within the normal range), there in another adjustment that needs to be done. One needs to adjust the second curtain's spring to ensure even exposure and full frame opening. So the speed accuracy and evenness of exposure across the frame are different things, as far as I know.

 

[Tom A]

The "shutter brake" can also cause this bounce problem. On older, double stroke, M3's it is quite common as they age. Problem with the DS M3 is that the brake mechanism is exclusive to that version. On later single stroke M3's the brake is common with the subsequent M's.
This was also the problem with the first series of M4-2's - a crescent shaped "exposure" on the left hand side of the negative, This usually happened at speeds 1/250 and higher. It can be adjusted as can the M3 (though lack of parts usually requires it to be converted to single stroke).
First try to see if a technician can adjust the shutter to work properly - otherwise have the brake changed.

 

[mojobebop]

It is a very common problem, known as shutter tapering. Both curtains have their own tension wich must be adjusted properly. A compentent repairman can do the adjustment in a few minutes.

Erik.

--------------------------
if a 'common' problem on latter; (m7-mp)
i would find this troubling.
being that the cost of the camera is approx 4500.00.

 

[Erik van Straten]

--------------------------
if a 'common' problem on latter; (m7-mp)
i would find this troubling.
being that the cost of the camera is approx 4500.00.

Well, normally when adjusted the shutter will stay like that for many years. But as a routine, a repairman should allways check a camera on this problem.

Erik.

 

[marduk]

The "shutter brake" can also cause this bounce problem. On older, double stroke, M3's it is quite common as they age. Problem with the DS M3 is that the brake mechanism is exclusive to that version. On later single stroke M3's the brake is common with the subsequent M's.

That's interesting. This was the problem with my older DS M3 when I received it. I didn't know that mechanism was changed in SS M3 though.

 

[David Murphy]

Shutter taper (or related phenomena). I believe that the pro grade shutter testers diagnose this immediately - I have several cameras repaired with this problem

 

[ryan26]

My m6 has a different problem at 1/1000th of a second. I get an over-exposed band across the entire top edge of the frame, probably 1 or 2mm thick. Seems funny considering it's a horizontal shutter, but maybe others have experienced this as well?

I've just been avoiding that speed, and putting off a full CLA because I don't want to be without my camera!

 

[Erik van Straten]

Can be there is a flock of dust on the side of one of the shutter curtains (or on both), so the form of the slit is uneven. This causes normally at high speeds uneven exposures in horizontal bands over the frame, because the slit is very narrow then.

Erik.

 

[ItsReallyDarren]

An update on the camera. It seems the shutter indeed had a tension problem. After getting in touch with Youxin he suggested I send the camera back for him to take a look. The camera came back earlier this week with a readjusted shutter.
According to Youxin the left to right travel speed of the shutter was off. No word from Youxin about the brake so it feels like its working just fine.

I plan on running a test roll to see how faster speeds turn out but I have a feeling the shutters going to behave just fine.

 

[bobkatz]

I get an overexposed vertical zone with 1/1000 on my canon 7s after CLAed by Sherry I think the curtain bounces exposing a little bit more??
Bob.