Re: [APML] Camera testing

["Michael Barlow" <mikeba@rochester.rr.com>]

    First, Kent..  Once you mentioned the focusing aids I realized I
miss-typed.  In fact I have a heartman mask for the LX90 but I haven't used
it but once or twice.  I shouldn't have mentioned Focusing directly as much
as flaws in focusing..  I used a magnifier to focus on the Moon once and
still came out slightly out of focus enough that the guy who scanned it and
used to do this all the time with his photo's pointed it out to me, that it
could have been focused a bit better.  So that makes me think that there's a
~possibility~ the focusing screen could be off just enough that when it's
focused in the view finder it's not focused at the film plane, or there
could be other reasons.  Which gives me the idea that if I had a good day
time pattern to work with I might be able to figure this out.  It might even
tell me if the film it self isn't seated right and it's getting curled up
slightly giving me more vignetting then there should be, or many other
possibilities.  I believe my only problem with setting such a test up would
be the pattern,  what would be best?  Something with perfectly strait lines
would help in many ways, I know I'd have to find something with good clean
and clear lines but I can't think of any other possible parameters or other
patterns to find other flaws with the system.

Gene, Sounds good that someone else may have done such a test and hopefully
someone will chime in with details:-)
Michael A. Barlow

----- Original Message ----- 
From: "Gene Horr" <genehorr@houston.rr.com>
To: "'Michael Barlow'" <mikeba@rochester.rr.com>; "'Discussion of Film
Astrophotography'" <astro-photo@seds.org>
Sent: Thursday, February 24, 2005 2:18 PM
Subject: RE: [APML] Camera testing


> Somebody did this several years back, but his name is drawing a
> blank right now.  He did a version of the US Army optics test
> patterns in Corel Draw.  Perhaps someone here has a copy of it?
>
> Gene Horr

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