Archived posting to the Leica Users Group, 2005/09/27

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Subject: [Leica] Foto with my IIIf and Voigtlander 35mm
From: cochranpr at mac.com (David Cochran)
Date: Tue Sep 27 12:22:29 2005
References: <3ee867269fbf5740278a4b99eaed93b1@mac.com> <4339906E.9030706@summaventures.com> <013301c5c397$0c1afb20$2501a8c0@chartertn.net>

Hi JB....THANKS!...
Now a question...CLB?  Cleaning, Lubricating and  B?


peace


D. 
On Tuesday, September 27, 2005, at 12:12PM, John Black <jblack@ambio.net> 
wrote:

>
>
>> >
>> > The film is showing streaks on bright areas, although they are
>> > intermitent. My guess is that it is the curtain..I don't know. After all
>> > I will have to send the camera for check-up.
>> >
>> > Here it is....
>> >
>> > http://www.photo.net/photodb/photo?photo_id=3760181
>> >
>> >
>
>I think I know exactly what that is...  Had the problem with LTM cameras
>myself.  I'll bet the shutter speed was high, perhaps 1/500 or 1/1000.  If
>you will notice, the fabric of the curtains is wrapped around the end of the
>blind edges and sewn, unlike M camera blind edges which have metal "lips".
>When set to very high speeds, the shutter merely creates a very narrow
>"slit" between the first and second curtain that travels across the film
>plane.  When shutters get old and need readjustment, the slit is too small
>and the texture of the fabric creates "bumps" in the slit that double or
>halve the effective speed by narrowing the gap.  Normally this is not a
>problem as the slit is wide enough that the fabric texture only accounts for
>maybe 10-20% variation, not 50%.  The M shutter corrected this by providing
>a sharp, smooth metal edge for the traveling slit.
>
>Get a good CLA and it will go away.
>
>JB
>
>
>
>
>_______________________________________________
>Leica Users Group.
>See http://leica-users.org/mailman/listinfo/lug for more information
>
>

Replies: Reply from jblack at ambio.net (John Black) ([Leica] Foto with my IIIf and Voigtlander 35mm)
In reply to: Message from cochranpr at mac.com (David Cochran) ([Leica] Foto with my IIIf and Voigtlander 35mm)
Message from pdzwig at summaventures.com (Peter Dzwig) ([Leica] Foto with my IIIf and Voigtlander 35mm)
Message from jblack at ambio.net (John Black) ([Leica] Foto with my IIIf and Voigtlander 35mm)