Ok - Here is the final result on my Jellyfish. I managed to grab another 20 frames on Friday night so image is now total of 53 X 5mins subs with my Atik 16ic through WO ZS66 with 0.8X flattener. Additional frames didn't really add any to the detail but has helped smooth the background some... Time to move on to something else. For reference I've also posted an unprocessed (other than levels) single raw 5min sub... I need to capture more photons & so need to either go for larger aperture scope or shorter focal length or a less light polluted location... :-(
I'm still not 100% pleased with this - seems to lack the 'wow factor' of Robert's & the like images. Any comments appreciated.
Cheers, John
(http://homepage.ntlworld.com/john.punnett/graphics/oas/Jellyfinal-1.jpg)
(http://homepage.ntlworld.com/john.punnett/graphics/oas/5min_raw.jpg)
John, Wow! that's nearly 5 hours exposure time ! There's wonderful detail there, perhaps it could be sharpened just a knats more (I think the image could take that). Regarding noise, you might find that most of the background is in fact nebulosity !
You're right about the LP, mine's about to take a quantum leap when the new Tesco's opens due south :(
Is this image in Ha ?
Thks Robert - yep nearly 5hrs you inspired me with the 13hrs on your rosette.....
Below is a 0.3 pixel radius unsharp mask - Hopefully this is the 'knats' you mean...
It was taken with my Ha filter - Astronomik 13nm
I know what you mean about Tesco's - I had one open about 500m from (as the crow flies) - Although it is a medium sized Tesco it keeps sociable hours & is normally closed by 8pm so lights not too bad...
Thks again, John
(http://homepage.ntlworld.com/john.punnett/graphics/oas/Jellyfinal_Sharpen.jpg)
Well John, I think that is very nice. Smooth, well focused & guided, not a lot of noise & the little bit of sharpening made a difference.
Thks Fay, I appreciate your comments. I should have done 10 or 15min subs though... John
Yes, I would like to do 10-15 mins , but it makes me a bit nervy!!!!! My heart would be racing at the end of each sub in case it was no good.
I do wonder if I could have done it on my Rosette the other night though. Only got 3x5 because of cloud.
Haven't got the confidence of Robert.
John, that looks looks better - not much in it but enough to make a difference.
I take it you've read this review of the 16ic ... http://www.stark-labs.com/craig/articles/assets/Atik16IC_API.pdf (http://www.stark-labs.com/craig/articles/assets/Atik16IC_API.pdf)
QuoteHaven't got the confidence of Robert
Fay, now your guiding is sorted just get on and do some... and you John !!!
John, that's a great image! It's a very faint target and you've managed to bring out a whole load of detail. The extra bit of sharpening definitely made a difference.
It's interesting to see that single raw sub - it does show how swamped by noise you are. So to get such a noise-free final result is quite an achievement.
Mark
Will do, Robert, next time out, Canon/ Rosette!
That looks ok John, any chance of getting the Subs on Friday so I can have a go at processing it?
Cheers Robert, Mark, & Chris I appreciate your comments. Thks for the link as well Robert (I haven't seen this) & your help yesterday.
Chris - feel free to re-process I will get you the files. My process was with NO calibration frames at all - No darks, bias's or flats. All I did was average stack the lights...
John
John, I have a master of a stack of 30 bias frames and I find this helps significantly in reducing the fine image noise. You might benefit from trying that (suggest at least 30 but I was lazy), it doesn't take long as they are zero length subs and you can do it indoors so definitely worth a go. Average them all together to create one master bias and use that for calibration.
From that review the 10 min dark increased the signal by 10 counts so it's pretty insignificant and could probably be ignored.
Would also suggest the SD-Mask stacking algorithm.
Robert
Very nice John. Plenty of detail in that.