Olympus-OM
[Top] [All Lists]

Re: [OM] New lens tests posted

Subject: Re: [OM] New lens tests posted
From: PCACala@xxxxxxx
Date: Mon, 26 Jul 1999 18:34:49 EDT
Mike H. writes:

<< I don't know if you've addressed this before, as I'm new to the list, but 
can 
you explain why the OM-1 shutter has affected some of your lens tests in the 
wide apertures only? Why don't they affect the results across the whole 
aperture range? >>

Perhaps there is a jolt that occurs when the camera's auto aperture linkage 
meets the lens rear diaphram linkage and it can't travel anywhere because the 
lens is set at full aperture.  Likewise, the action might be dampened the 
further the linkage travels (i.e., the more the lens is stopped down).

At wider apertures, the shutter speed is faster.  Perhaps during the time the 
film is being exposed there are stronger and/or more cycles of residual 
harmonic vibrations at, say 1/250th sec. (= f/2.8), versus 1/8th (= f/16).

<< And what is it about the OM-2000 that improves this? >>

1. Mirror and auto diaphram prefire as soon as the self timer is released 
(i.e., 2 to 10 sec. before exposure). 
2. A vertical shutter with less travel distance.
3. Seemingly less body flex than an OM-1 when mounted on a tripod screw, due 
(?) to the tri-metal alloy used in the OM-2000.

There is a lot of speculation on my part in these responses.  I'm hardly an 
mechanical engineer.

Gary Reese
Las Vegas, NV

< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >


<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz