Thanks for the info. I have only made two attempts at astrophotography (at
star parties this year), so I am rather inexperienced, but people tell me that
my refractor will change with temperature changes, and thus I will need to
refocus between each shot. Since my refractor has fluorite, several people have
told me that it experiences even more focus adjustments. I once posted this
fluorite claim on s.a.a and was told by both Roland C. and Thomas B. that
this is not the case.
----- Original Message -----
Sent: Saturday, November 08, 2003 2:50
PM
Subject: Re: [APML] Medium format cameras
(was:Tak. FSQ-106 for mediumformatfilm?)
Phil,
once you've used the ground glass/FM-60 combo to focus the camera....(
withouth the film loaded ) you probably wont have to refocus again for
your nights photo session....any temp swings are not going to affect the focus
enough to worry about it.........UNLESS you are using LONG FOCAL LENGTH
scopes........(2000 mm focal length and up )
I have shot pentax 6 x 7 using a/p 155 f 7 and Tak FSQ
106 mm f-5 and never changed focus during a session of
shooting.........and never have noticed difference in focus on the
stars........ MAYBE if you used a magnafying loop on the negative
you might notice some SLIGHT differences...........but on 6 x 7
format ,,,,,,,,,,,,,printing a 4 x 6 print the enlargement isnt very
much......this no critical visual differences in focused star
appearances
Broose K
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