|
Thanks for the pics Matt, this helped me allot. Now that I know what it is supposed to look like I realise that I can see this but it is is being drowned out by large amounts of flaring which is even worse with my 6.5mm EP.
I posted on the general chat forum for some help in borrowing an EP to test my scope. I got some good help from the Brisbane Astronomical club on Friday night. They pointed me to Astro Petes at Mt gravatt. I meet up with them on Saturday night and we had a good look at my scope.
We collimated it with a laser collimator and tried some different EP's. To my disappointment the problem seems to be with the scope and not the EP's. My EP's worked ok in one of Peter's 8" Dobsonians and using his EP in my scope showed the same bad flaring out of focus image that my EP has. We were looking at Jupiter and we just couldn't get my scope to focus properly.
Just when its about to come into focus it just doesn't quite make it then it starts going out of focus again. there was four or five guys looking at my scope and no one could put their finger on what is wrong with it. I guess it really boils down to either the primary or secondary mirror's. My scope is a very fast f 3.7 - 8" FL 750mm like Pinwheel's and the secondary mirror is about 100mm x 70mm which is probably worth trying to replace before giving up on the scope. A primary mirror is probably not worth replacing since you can by a new Dob for about $500.
If any one has any suggestions I'm all ears.
Thanks for your help
TAHAIC
|