Setup scope, focuser etc on Friday night, when I had a break in the clouds.
Test shots of Omega Centauri, I like to use a glob as a system test, shows all the horrid things first. A quick starfield test somewhere in Sag showed near perfect collimation and a pretty flat field in CCDInspector. This is taken with the scope as it arrived, straight out of the box.
Well, the first test looks not toooo bad I guess?...but I'd want to see a little better than this from a high quality corrected RC in due course.
I'm sure this will eventuate
Mike
The weather, though clear is not so good tonight Mike. The seeing is rubbish. I also haven't quite sorted out the balance of the scope. Having said that the field is pretty flat and the stars are measuring at 2.8 - 2.9" FWHM.
I'm also running outside the backfocus distance, which will degrade the image a bit, I'm led to believe.
Hi Stuart,
There is, as you say, nothing to do about the star sizes, that is the burden of high res imaging. But I would look closely at collimation since there seems to be a bit of astigmatism (worse at the top than the bottom? hard to say without closeups).
Great field. Don't stress too much about CCDIS measurements. They will vary greatly depending on what you image. A bright cluster like this will show a depression in the middle of the field when it's not really there. In my experience alway stick to a bright central star and a uniform background . Rigel cent is a good candidate. Not too bright and lot of background stars uniformely distributed. And it's nice and up right now, easy to align too. Shoot 120s subs then measure, tweak, re-shoot the same field another night and see the differences from one session to the other.
Given the standard of your usual images , you will have the new gear singing along in no time, look forward to the results.. I didn't see anything wrong with the image here anyway.
Looks Good Stuart, you should have some fun with this extra focal length.
An extra 200mm focal length I won't notice too much, the extra 2" of aperture I will. The new scope is f/7.3 vs f/8 of the GSO.
Quote:
Originally Posted by Paul Haese
Nice work Stuart. Who is the manufacturer?
Deep Sky Instruments
Quote:
Originally Posted by multiweb
Great field. Don't stress too much about CCDIS measurements. They will vary greatly depending on what you image. A bright cluster like this will show a depression in the middle of the field when it's not really there. In my experience alway stick to a bright central star and a uniform background . Rigel cent is a good candidate. Not too bright and lot of background stars uniformely distributed. And it's nice and up right now, easy to align too. Shoot 120s subs then measure, tweak, re-shoot the same field another night and see the differences from one session to the other.
Hi Marc, the field curvature etc was generated on a series of 15 1 minute subs on a randomish field, well Pluto's in the middle of the field. See attached Field Curvature Map, shows I need to tweak the collimation a little.
Quote:
Originally Posted by Alchemy
Given the standard of your usual images , you will have the new gear singing along in no time, look forward to the results.. I didn't see anything wrong with the image here anyway.
Thanks Clive, flattery wins everytime. The colour seems off in the image, I'm gunna do a Sidonio on it sometime...
