My First Rosette

[Ags]

1300 seconds or so of exposures, taken from a Bortle 6 location in the Brecons.

340 x 4 second frames, 100 darks, no flats.

ASI 485 MC, Gain 300, Astronomik L3 filter.

Zenithstar 66 reduced to f4.3.

Edited February 25, 2022 by Ags

[Rodd]

Heck of a first.  Very nice.  Broadband nebulae are the toughest gig....at least for me with a mono camera.  I am not familiar with OSC--thiough I have heard that once the stacks are made after debayering, its teh same processing.  I don't know.  But it looks great.  BTW Even if you don't have obvious dust bunnies or other major belmishes, flats improve an image.  

[Elp]

Pretty damn impressive for 4s exposures.

[Ags]

I am stunned by what I can get with the ASI 485 MC with very short subs. Coming from a mono camera (178 M) I was concerned about loss of sensitivity when moving to OSC, but it almost feels like I capture more data with the OSC. It's not mathematically possible, but that's how it works out for me.

If I can just get more time on target I can easily improve, 1360 seconds is nowhere near enough. I was going to get another hour tonight, but the evening has been stolen by pre-flight covid paperwork instead. I am however pretty pleased with the capturing regime, which involves rough alt-az alignment of my AZ-GTi (point and track actually, not goto) and a little course correction every ten minutes or so. The only limiting factors are the hard disk space needed, and the processing time in Astro Pixel Processor given the hundreds or thousands of subs.  

I would like to go for longer subs (12 seconds ha ha) but for that I need to be a bit more careful in setting up the AZ-GTi.

@Rodd I normally do flats, but didn't have a chance last night (just family commitments). I will do better next time 😀

Edited February 25, 2022 by Ags

[Rodd]

8 minutes ago, Ags said:

 I normally do flats, but didn't have a chance last night (just family commitments). I will do better next time 

Well--no flats are better than bad flats!  I hate that when it happens.  Sometime I shoot flats immediately after collecting the subs and they will just be bad--dust bunnies not even close to where they are in the subs.  One time it was cuased by ants!  A nest of ants made their residence in my reducer threads and every so ogten one would crawl across the lens.   

[Ags]

It's interesting to compare my slacker effort to an APOD from 1996...

https://apod.nasa.gov/apod/ap960522.html

How technology moves on!

Edited February 25, 2022 by Ags

[Elp]

@AgsIf you setup autoguiding with the azgti in EQ mode it opens up a whole new avenue. I've done 5 minute exposures at a push (stars are a little misshapen).

Your progress makes me want to try my 224 on DSO.

[Ags]

I'm not convinced of the advantage of long subs, given the low read noise and high QE of modern CMOS cameras. I think what I need to focus on in is increasing total integration time. 

I have tried EQ mode but I need a few more bits to avoid scope-tripod collisions. 

Edited February 27, 2022 by Ags