Olympus-OM
[Top] [All Lists]

Re: [OM] Extension Tubes

Subject: Re: [OM] Extension Tubes
From: Chris Trask <christrask@xxxxxxxxxxxxx>
Date: Thu, 12 May 2016 11:10:03 -0700 (GMT-07:00)
     Something like that.  There isn't enough flange thickness to allow 
removing enough material to justify the effort.  The amount of movement needed 
by the catch release dictates the body thickness. For the OM lens release it's 
a sideways action, so you need far less body thickness.

     I just received my two OM extension tubes in the mail, and tomorrow I 
should be able to post some results.  Looking though all of the books that I 
have on nature and close-up photography I was not able to find any mention of 
how to calculate the maximum focal distance for a given extension, but I did 
find an equation to adjust the f-stop for a given extension.  For 5mm you 
decrease by 1/3 and for 10mm you decrease by 2/3.  I was already familiar with 
the shutter speed adjustments between close-up lenses and extensions, so this 
was no great revelation.

>
>But I would expect you and your machine shop to fashion a solution. 
>Depending on how deep the springs go on the front side of the pins I 
>think you might be able to machine 3mm off the backside.
>
>On the other hand, maybe it's that spring action requirement on the pins 
>that makes the minimal depth of the tube 10mm.
>


Chris

When the going gets weird, the weird turn pro 
     - Hunter S. Thompson
-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/


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