M83 - first light f/4 newt and Atik 420

[Lee]

Hi all
Finally got a chance for an image with the new f/4 200mm 'astrograph' newt, and the Atik 420 monochrome CCD.

This image is 11x5min luminance only, I'm pretty happy with it - scope straight from the shop, not collimated, no coma corrector in place. Collimation looked reasonable through my broken Cheshire.... Guiding with PHD and a side mounted 100mm f/5 achromat.

CCD cooled to 10 deg C, 3 dark frames used in processing with nebulosity.

I was going to fiddle with the MPCC last night, but when I saw the first few frames pop up I pressed on, clouds are never too far away around here!

I'm after some thoughts on coma/collimation - I can see some coma like distortion, although the upper left corner seems less affected, maybe some guiding glitches also.....

No RGB any time soon, the 'astrograph' doesn't have enough back focus to accommodate the filter wheel, so a moonlite will be added at some point....

[Shiraz]

what an excellent first light image - looks like it will be a very good system when you get the minor alignment bugs sorted.

might possibly be a bit of image plane tilt - focuser maybe? First thing to do though is collimate - it is a bit out and you will not be able to assess any other possible alignment problems until you do that.

[A23649]

Hope you don't mind but i had a little bit of a play with your data in startools and got this:

Nathan

[Lee]

I don't mind at all, I might have to check into StarTools some more.... what did you do to it?
I can send you the FITS if you'd like a crack at some better data, rather than the jpg..... :)

[h0ughy]

nice beginnings Lee. hope you get the scope sorted soon

[alistairsam]

hi Lee
I'd like to have a go at your raw data as well.
there is some nice detail in there but I'm surprised at the lack of coma as I have an F4 and coma without a cc is usually quite prominent.
unless your pixel size is small or its cropped.
dropbox would be the easiest as you could then post raw subs
cheers

[Lee]

No problem.... just post your results here, with instructions.... :)

Posted a 35MB zip to my webspace (http://files.astrodog.eml.cc/files/).... there is 11x5min subs in the zip archive, only processing is dark subtraction through Nebulosity....

I think there is some coma there, the small chip minimizes it somewhat though...

[alistairsam]

Hi
This is only a minor tweak, but i think there is more detail in there
https://www.dropbox.com/s/nzs4fr2ju6xmb8x/m83-2.png
I'm not able to stack them in dss for some reason, turns up almost white
Cheers

[Ross G]

Nice looking capture Lee.

Good luck.

Ross.