Bobby,
I have no technique for focusing!
J Really,
since this was only my 3rd attempt at prime focus I was
concentrating on guiding and only gave focusing a cursory look. Now I need to
do something to get it right since the guiding seems to
work.
There's several reliable
techniques; knife-edge and direct viewfinder magnification are the two top
methods. I use the direct viewfinder method with a 20 Celestron Erfle eyepiece
on my Nikon ecreen with the prism removed. It's not perfect but with some
experience it can be pretty reliable.
My OAG is a cheap Meade, I
really need a better one. I’d like to get a GEG, but that will have to wait,
I’m well over my toy budget.
I understand. The hobby can be a black hole for
$$ for a while <g> But the Meade OAG and the Meade focal reducer are
giving you some pretty good vignetting.
I know the Meade works, I proved it last
night, but finding a descent guide star was troublesome. Since I have 2 Canon
camera’s, do you think I could put one on the OAG with no film and use a true
knife edge(like a razor blade) to focus and then put the body on that has the
film?
Lots of people do that and I
tried that with a spare camera body. I'm not experienced enough with KE to be
able to use it better than my direct screen mag, but if one knows what he is
doing then KE is the most reliable. If you have access to an astronomy
club or star parties where someone can coach you in KE it will ultimately be
more exact.
Bobby
Middleton
-----Original
Message-----
From:
owner-astro-photo@seds.org
[mailto:owner-astro-photo@seds.org]
On Behalf Of
Bobby
Middleton
Sent: Thursday, March 07,
2002 5:48
PM
To: astro-photo@seds.org
Subject: Re: [APML] M42
Hi Scott. Your guiding looks good
and the mask is well done to preserve the core. I agree with you on focus;
you're probably a little soft. What's your technique for focus? The hypered
PPF color looks good. Was the grain OK? Are you using an OAG or
guidescope?
----- Original Message -----
Sent:
Thursday, March 07,
2002 3:10
PM
This is my latest attempt for
prime focus shots. My polar
alignment seemed very good and the ST-4 tracked the best I’ve personally
seen, A3’s and A4’s for the 28 minute shot and later A2’s and A3’s on a 20
minute shot.
I believe I was slightly out of
focus and I also had trouble trying to eliminate what appears to be
vignetting in the posted image. This was also my first attempt combing
images, Photoshop was the only post processing
used.
Comments and suggestions
please!
http://www.creatorsview.com/Pages/testimage.html
Thanks
Scott