M31 - First Attempts - DSLR & CMOS

[daemon]

Hi All,

 

I just wanted to share a couple of shots of M31 taken this weekend from here on the south coast of the UK. Andromeda is rising now, the nights are getting longer and I'm looking forward to Galaxy season.

 

Unfortunately I'm pretty constrained with time - other than needing sleep I tend to struggle with alignment and I am still really struggling with guiding, so these shots are based on very little exposure time and are still very much beginners attempts.

 

I did however want to try and compare my DSLR (Nikon D5300) with my relatively new ZWO ASI1600 Mono camera. So here are two images for you to look at - taken on different night's this weekend - unfortunately the clouds rolled in on Saturday - when I had the most time available - typical!.

 

The first one (DSLR) is a single sub. I had a pretty good Polar Alignment but was struggling with other alignment stars so just settled for plate solving to find M31 and took some shots before the tracking went wild on me!

 

The second one was similar (ASI1600). I plate solved after a pretty good PA and managed 4 subs (20", 60" 120" and 180" - all with Luminance filter) before once again the tracking gave up.

 

Sadly no time for calibration frames, so I just packed up and went to bed. Stacking (DSS) and processing (GIMP) done on the following days. Having said that, I shot some darks the next day with the ZWO. I realise this is probably a no-no but thought I would give it a try to see if I could get rid of some of the noise. So the ZWO image does have some darks applied, but probably to no avail, as there is still a LOT of noise. I guess I'd also really benefit from flats (yes, even I can spot the dust bunnies!)

 

The next thing is Coma (& maybe field rotation?). I fitted my Coma Corrector to both the DSLR and the ZWO, but (especially with the ZWO) I am not sure if it is in the right place in the imaging train. Maybe I'll post a pic of my imaging train one of these days to get some advice.

 

Finally, my processing skills leave a lot to be desired (being colour blind doesn't help 🙂 - so I have used quite a bit of artistic license (even resorting to using a basic Windows photo filter! Aghhh!}.

 

Anyway, I've waffled on long enough. Thanks for looking and clear skies!

 

Daemon Steve.

 

1) Sky-Watcher 150PDS, SW EQ6R-Pro, Nikon D5300 (un-modded) Baader Coma Corrector. Single Sub, 300" exposure  ISO 640. No Guiding, only tracking.

 

2) Sky-Watcher 150PDS, SW EQ6R-Pro, ZWO ASI1600M Pro, Baader Coma Corrector, Luminance Filter, 4 subs (various exposure lengths) Gain = 139. No Guiding, only tracking.

 

[LordLoki]

Hi daemon, 

Nice pictures I am surprised how good they came out even without calibration frames. I am a beginner too and my first attempts did come out fairly poorly. 

Post processing mostly made it worse. Couple of weeks ago I even asked here in the forum if I should get a new camera but people told me most likely the error is somewhere else. 

Previously I was just using 5 darks no bias no flats etc. On Monday I also went for a shot at M31 this time with all the calibration frames and it came out much better. 

30 lights 640 ISO 240s  unguided. 10 darks 40 bias 30 flats on Canon 60d unmodded. Edit: scope is explore scientific Ed80 and sky above my house is bortle 4

First pic is after stacking with 1 quick stretch in Adobe Photoshop

Second pic is after a bit more of processing which I am a total noob in but I find its not too bad. 

 

 

Edited August 28, 2019 by LordLoki

[daemon]

Thanks for the comment LordLoki, and you have got some good shots there - especially the second one.

Your stars are a bit rounder than mine so I guess your tracking/guiding was better.

My tracking is normally good as long as I get my alignment right - I think I took a few too many shortcuts last weekend.

And yes, I really must be more diligent with the calibration frames in future.

Clear Skies!

 

[ollypenrice]

I think both images are heavily black clipped. This happens when you bring the black point slider in too far the the right. It can be tempting to do this to remove LP gradients - but resist that temptation!

This image is black clipped. The histogram peak has no flat line to the left and the sky is jet black. 

This one is healthy. There is a flat line to the left of the histogram peak. The sky is fairly light and the faint outer parts of the galaxies have not been discarded.

Olly

Edited August 30, 2019 by ollypenrice
Typo

[daemon]

Thanks Olly. It seems that I am a repeat offender when it comes to clipping! I will try again with processing when time permits.

If I am able to gather more data for stacking then this will perhaps reduce the temptation to over clip the black point.

Regards,

Daemon

 

[LordLoki]

On 30/08/2019 at 08:53, ollypenrice said:

I think both images are heavily black clipped. This happens when you bring the black point slider in too far the the right. It can be tempting to do this to remove LP gradients - but resist that temptation!

This image is black clipped. The histogram peak has no flat line to the left and the sky is jet black. 

This one is healthy. There is a flat line to the left of the histogram peak. The sky is fairly light and the faint outer parts of the galaxies have not been discarded.

Olly

I know it's a while ago but I just saw this. Thanks for the feedback I just started with editing and thankful for any tip. 

[MimasDeathStar]

On 26/08/2019 at 23:57, daemon said:

Hi All,

 

I just wanted to share a couple of shots of M31 taken this weekend from here on the south coast of the UK. Andromeda is rising now, the nights are getting longer and I'm looking forward to Galaxy season.

 

Unfortunately I'm pretty constrained with time - other than needing sleep I tend to struggle with alignment and I am still really struggling with guiding, so these shots are based on very little exposure time and are still very much beginners attempts.

 

I did however want to try and compare my DSLR (Nikon D5300) with my relatively new ZWO ASI1600 Mono camera. So here are two images for you to look at - taken on different night's this weekend - unfortunately the clouds rolled in on Saturday - when I had the most time available - typical!.

 

The first one (DSLR) is a single sub. I had a pretty good Polar Alignment but was struggling with other alignment stars so just settled for plate solving to find M31 and took some shots before the tracking went wild on me!

 

The second one was similar (ASI1600). I plate solved after a pretty good PA and managed 4 subs (20", 60" 120" and 180" - all with Luminance filter) before once again the tracking gave up.

 

Sadly no time for calibration frames, so I just packed up and went to bed. Stacking (DSS) and processing (GIMP) done on the following days. Having said that, I shot some darks the next day with the ZWO. I realise this is probably a no-no but thought I would give it a try to see if I could get rid of some of the noise. So the ZWO image does have some darks applied, but probably to no avail, as there is still a LOT of noise. I guess I'd also really benefit from flats (yes, even I can spot the dust bunnies!)

 

The next thing is Coma (& maybe field rotation?). I fitted my Coma Corrector to both the DSLR and the ZWO, but (especially with the ZWO) I am not sure if it is in the right place in the imaging train. Maybe I'll post a pic of my imaging train one of these days to get some advice.

 

Finally, my processing skills leave a lot to be desired (being colour blind doesn't help 🙂 - so I have used quite a bit of artistic license (even resorting to using a basic Windows photo filter! Aghhh!}.

 

Anyway, I've waffled on long enough. Thanks for looking and clear skies!

 

Daemon Steve.

 

1) Sky-Watcher 150PDS, SW EQ6R-Pro, Nikon D5300 (un-modded) Baader Coma Corrector. Single Sub, 300" exposure  ISO 640. No Guiding, only tracking.

 

2) Sky-Watcher 150PDS, SW EQ6R-Pro, ZWO ASI1600M Pro, Baader Coma Corrector, Luminance Filter, 4 subs (various exposure lengths) Gain = 139. No Guiding, only tracking.

 

 

They're amazing well done! Do you have any tips for working on GIMP? I'm still struggling to get to grips with it. Have you any tips for light pollution / gradients? 

Thanks and keep up the good work!