M8/M20 from Astrofest

[troypiggo]

My first Astrofest (http://www.qldastrofest.org.au/), and these were captured on the first of my 3 nights there. Had an absolute ball. Learnt so many things.

Still need to work on my post processing skills. Paul [1ponders] from IIS (http://www.iceinspace.com.au/forum) was kind enough to spend some time with me showing his processes and I have tried to implement what I learnt.

I think I have come to realise that if I'm going to be pushing, stretching, trying to get the absolute most out of these astroimages I really need Photoshop instead of persisting with GIMP. To date I have not seen the need for it with my terrestrial type photography, because most of the histogram is pretty well spread already and I just do some minor tweaking. But I can see that trying to stretch this data to the max needs more than GIMP's 8 bit handling. You can see the data being dropped in the histogram as you stretch. Anyway...

I also found the MPCC still does leave some eggy stars in corners.

And there seem to be some horizontal scan lines or something in the 100% images, you may just be able to make them out here. Need to get to the bottom of that.

ED80, 40D (mod) and trying MPCC
ISO800, 10x4mins

http://piggo.com/%7Etroy/photos/2009/2009_08_19/M20_M8%20ISO800%2010x4m.jpg

[painful100]

wow, no comments yet? Great shot!

[Nighthound]

Great work Troy. Sounds like a good time at Astrofest.

I'm curious to why you are using a coma corrector with your refractor? ED 80 right? That would explain the less than flat field. The MPCC is designed to correct coma in Newtonians. I use one with my Vixen R200SS.

[troypiggo]

Thanks Steve. It was a great time. Got a few more images to process and post :)

I know the MPCC is intended for Newtonians, but was having the eggy stars in corners of my refractor and had read that some guys were using the MPCC on ED80s with some success in preventing it. Thought I'd try to see if it improves. It didn't.

I've also read good things about the Williams Optics Flatter II (not the III), but WO also have a new Flattener IV that's specifically designed for refractors like mine. I'm going to try it out.

[chris.bailey]

Great shot Troy. I would be wary fo the W/O FFIV as there are very mixed reactions on the W/O forums. Any field flattener has a very specific spacing requirement to the CCD, deviate much more than a few mm from that and the results can be worse than not having one at all. Getting at the required spacing info is another issue.

[troypiggo]

Thanks for the heads-up Chris. I do plan to do some more research on it first. Don't want to make another poorly researched purchase.

[Celestron]

Great shot Troy !!