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

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Subject: Re: [Leica] Compact M Motor - smearing image LHS
From: "Dante A. Stella" <dante@umich.edu>
Date: Wed, 08 Aug 2001 19:16:47 -0400
References: <B79719B6.13EB6%jbcollier@powersurfr.com>

Or the M6 needs to be designed around a high-speed coreless motor and a quartz
shutter.  But I guess someone already did that.

John Collier wrote:

> 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)
In reply to: Message from John Collier <jbcollier@powersurfr.com> (Re: [Leica] Compact M Motor - smearing image LHS)