I'm sure you are all bored of M31 images, but here is my third attempt. ADDED TIF DOWNLOAD LINK

[MKHACHFE]

Hi all

I am constantly amazed at what my cheap DSLR and slow telephoto can pick up. 

Details:

Canon 4000d unmodified
Canon 70-300mm at 300mm
F6.3
250x30s lights
1600 ISO
Star Adventurer Mini
Wonky tripod weight down (I desperately need a new tripod)

Bortle 6

Stacked in Siril
Initial processing in Siril
Further processing in photoshop

I took 25 flat frames but they seemed to make things worse, so I re stacked without using them.

I know, I know, my stars are way too overblown. I'm working on it. This already took 3 days to process, it's a very tough subject.

I know I can improve this a lot. This is my third M31 image and it's leaps and bounds better than my first one.

Thanks for looking and reading.

Edited August 19, 2020 by MKHACHFE

[michael.h.f.wilkinson]

Very nice. I think the background might be a bit too dark. That might clip some of the fainter outlying regions of the galaxy

[Adreneline]

3 hours ago, MKHACHFE said:

it's a very tough subject.

Nicely framed image. M31 is indeed a tough subject but also a rewarding one to image.

I agree the background is clipped. I downloaded your image and the PS colour sampler tool tells me your background is R:G:B = 0,0,0 - it needs to be more like 20,20,20. There is also quite a lot of jpg artefact noise in the image (quite apparent if you zoom in) which in my experience seems to arise if you convert and image the jpg rather than the tiff or raw master file (I assume your 250 lights are shot in RAW mode).

I've attached a zoomed in look at your image showing the background level and jpg noise compared with a similar image I took back in 2017 using a Canon 70D which might help to illustrate the points.

Why not upload/attach your stacked, unprocessed master image (as a tiff) and someone might have a go and see what they can find lurking in the data.

AP is a real challenge but definitely worth the effort.

Good luck.

Adrian

[MKHACHFE]

8 hours ago, Adreneline said:

Nicely framed image. M31 is indeed a tough subject but also a rewarding one to image.

I agree the background is clipped. I downloaded your image and the PS colour sampler tool tells me your background is R:G:B = 0,0,0 - it needs to be more like 20,20,20. There is also quite a lot of jpg artefact noise in the image (quite apparent if you zoom in) which in my experience seems to arise if you convert and image the jpg rather than the tiff or raw master file (I assume your 250 lights are shot in RAW mode).

I've attached a zoomed in look at your image showing the background level and jpg noise compared with a similar image I took back in 2017 using a Canon 70D which might help to illustrate the points.

Why not upload/attach your stacked, unprocessed master image (as a tiff) and someone might have a go and see what they can find lurking in the data.

AP is a real challenge but definitely worth the effort.

Good luck.

Adrian

Hi Adrian. Yes, it was all shot raw etc, and edited in 32bit and 16 bit, but I do have an unfortunate habit of at the end of the night, transferring the image to my phone and playing around with it in Lightroom on Android. So yes...this a heavily edited jpg that would not stand up to scrutiny. I do have better higher quality images on my computer but I tend to post here from bed while lying here not being intimate with the missus 😂

 

I'd be happy to post the stacked tiff..I'll do that shortly. 

 

Thanks for your advice and critique

 

[MKHACHFE]

9 hours ago, michael.h.f.wilkinson said:

Very nice. I think the background might be a bit too dark. That might clip some of the fainter outlying regions of the galaxy

Thanks for the advice.

[MKHACHFE]

As suggested, here is a download link if anyone is interested in seeing what they can coax out...

https://we.tl/t-36jYX2HNKI
 

Cheers

[Wyvernp]

Had a quick play in Pixinsight and there's actually quite a bit of data here! It looks like you have a bit of coma which is deforming the stars, I haven't used camera lenses for astro so not sure I can advise what is the cause.

Anyway here's my take on your data.

[MKHACHFE]

18 hours ago, Wyvernp said:

Had a quick play in Pixinsight and there's actually quite a bit of data here! It looks like you have a bit of coma which is deforming the stars, I haven't used camera lenses for astro so not sure I can advise what is the cause.

Anyway here's my take on your data.

It's interesting that you went for a more subtle look. I did consider that approach as well, but ended up with what I posted. I much prefer your core too mine and your stars are also much better. I guess it's a trade-off, brighter galaxy means brighter stars unless one uses 2 processed images and composites them.

 

Thanks for playing with my file. Good to know there is a lot of data in there. The coma is sadly a big issue with this lens. It's awful..but it was a "free" lens, having belonged to my late father in law and I have no money to buy anything better at the moment...

 

Cheers