Archived posting to the Leica Users Group, 2001/08/08

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Subject: Re: [Leica] Compact M Motor - smearing image LHS
From: John Collier <jbcollier@powersurfr.com>
Date: Wed, 08 Aug 2001 16:30:46 -0600

The problem is not with the drive but with the camera. It needs to have
mechanism that allows the motor to move after the shutter has completed its
cycle, and, prevents the shutter from firing until it has finished winding,
adjusted. This is a very common problem which results in all sorts of
shenanigans: cameras locking up, uneven exposures, etc. The M camera needs
to be redesigned with a simple electric interlock rather than a mechanical
one.

John Collier

> From: Andrew Nemeth <azn@nemeng.com>
> 
> A while back I reported that motorised sequences taken with
> the new Compact M Motor would smear the left hand side of
> shots following #1 in the sequence.
> 
> Finally had some time to test this and can confirm that yes,
> it's a real problem at all shutter speeds when you have the
> motor set to the quiet(er) "I" setting.
> 
> What appears to happen is that the shutter opens prior to the
> low-tourque-wind film has fully coming to rest, resulting in
> the LHS side of the frame being motion blurred.  The proprortion
> of the frame ruined of course varies with the s/speed.  At 1/250th
> only @ 1/8th of the frame is ruined.  At 1/125th almost a third
> of the image gets smeared.
> 
> However, set the motor to the louder & faster "II" setting and
> the smearing is gone, at all s/speeds.  Here because there is
> no low-tourque monkeying about, the film is in place and
> stationary when the shutter curtain opens.
> 
> So the moral of the story is: use "I" for one-off frames and
> stick to "II" for sequences.
>

Replies: Reply from "Dante A. Stella" <dante@umich.edu> (Re: [Leica] Compact M Motor - smearing image LHS)