M20, from Astrofest

stanlite (Grady) · #1 20-09-2010, 11:06 PM

given the nuclear winter that is rolling through queensland at the moment i have been given a chance to process some of the shots i have taken. This was taken over 2 hours up at Astrofest. Some guide issues i believe and other minor things. Main goal was getting the lanes o stand out. Taken with a 8" newt on NEQ6pro mount using a unmod 1000D. As always helpful hints are welcome as i am still learning. Cheers all. image is 6.3meg.

http://i944.photobucket.com/albums/a...20highiris.jpg

David Fitz-Henr · #2 22-09-2010, 07:59 PM

Quite a pleasant image Grady. The colours aren't bad either. I did a little bit of imaging with an unmodded DSLR when I started and found it a bit insensitive to red light; and it also looks like the blues came out stronger here as well. There appears to be a little bit of star flaring in the corners - do you use a flattener (Paracorr?) with your 8" newt?

Screwdriverone (Chris) · #3 22-09-2010, 09:15 PM

Hi Grady,

Interesting to see an almost identical rig take a shot of M20, one of the three I have done so far with my BD200N 8" on the HEQ5 and the 1000D. (I have attached my go at this for comparison, which I rotated and flipped to be the same orientation as yours so its easier to flip compare)

First thing I noticed was the dreaded coma at the outer 1/3 edge of the field, something which is inherent in the setup, due to the fast mirror and the largeish sensor on the 1000D, you could improve this with an MPCC, which I am yet to do myself.

Second, you say over two hours, but is that two hours worth of data? or a number of shots take in a two hour period? There seems to be less red in the main section than in my shot. Don't know if that's because I only have 4.5 minutes in mine (9 x 30 sec). Also, what ISO did you use? Your star colours are more detailed as you can see in yours a distinct blue hue in the NW bright star which shows as white in mine.

I am not sure if the 8" you have is an F5, or you have cropped the image as my field is much wider?

Overall though, an impressive result, perhaps if you have significantly more data than me, the red area pics up more of the blue, I don't know, but its a damn fine effort all the same.

Cheers

Chris

Hagar (Doug) · #4 22-09-2010, 09:18 PM

Nice image Grady. If anything I would say maybe a little overly sharp or overworked. I don't know if you are using some form of corrector but if so you will need to spend a bit of time to get the spacing just right which will fix the stars in the corners. Otherwise quite a pleasing image with lots of great detail.

stanlite (Grady) · #5 23-09-2010, 03:24 PM

hey thanks guys for your replies. to answer some questions ... no i don't have a flattener. My scope is a f5 (tube modded to reach prime focus). At the time i was using 1.25" adaptor maybe why i have a smaller FOV i also croped heavily because of a rather poor align on a meridian flip. Although i now have a MPCC at the time of this image i did not so the stars at the edges are being naughty lol. i thought the image is a little overally sharp to but i was trying to get the dust lanes to stand out more as i was displeased with my first result (which did ok on the red light and highlights but poorly on the fine details i thought) Here it is http://i944.photobucket.com/albums/a...20finished.jpg this is the same image just different processing done (also more corped as i was using it for my computer background). as you can see lots more detail and a bit more red but you lose the structure in the dust lanes i think.