Quote:
Originally Posted by Ross G
Hi Allan,
Shooting from a light polluted driveway.....I know your woes and desperation!
However, despite that, you have a very good photo, Disregarding the pollution gradients, it looks very sharp and well tracked and there seems some nice colour buried in there.
You've got a great grasp of QHY9 and RGB imaging. I'm still not game enough to try mine with RGB colour.
Good luck.
Ross.
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Thanks Ross,
Why aren't you trying RGB imaging?
I will shoot from the driveway until I iron out some bugs.
I still need to do a lot of work to get better images.
I checked with Maxim DL & my FWHM figures are not good.
The best FWHM I was getting was 4.6 arc seconds
(after I correctly put in the pixel size of 5.4 microns & focal length of
1220mm which would give under ideal conditions 0.9 arc seconds)
Some stars on other frames were at 6.5 arc seconds.
Using Ha on other nights - which does give smaller stars - I have
got down to a FWHM of 2.5 arc seconds on short exposures.
There are many reasons:
The seeing in Melbourne is not good. e.g.
Jupiter is always a fuzzy ball with 2 lines through it from Melbourne
but on Mt Baw Baw at 5,000 feet it comes in sharp & clear
on the highest power eyepiece.
The EQ6 mount is not accurate enough & it's hard to drift align -
I can get it right for a north star at the equator on the meridian
but then it will be off when pointed in a southerly direction.
Maybe the mount is not orthogonal?
That means I have to use 1 second updates on the PHD guiding
which is causing the mount to be constantly moving to catch up with the star.
The focus was a bit out - I used a Bahtinov mask as
I couldn't get the focus sorted out using Ezycap software for the QHY9.
The Varilock spacer is hard to use - I need to work out
a method which won't take all night to get the correct spacing.
see it here:
http://www.flickr.com/photos/2471943...in/photostream
The secondary mirror also needs to be moved up or down as the flats
show it's not centralized.
What FWHM figures are you guys getting?