Beginner: M31 - 51 minutes integration

[R1k]

This is my 4th DSO after starting in the hobby in June. This attempt is my best to date. More than happy to receive feedback. Process and equipment below:

North West UK

1/8/20, 02.30am

Bortle 6 skies

 

Equipment:

- Canon 800d unmodified

- Skywatcher Evostar 80ED

- Altair lightwave 0.8x field flattener

- Rowan belt modded SW HEQ5-pro

 

Acquisition:

- No guiding, no acquisition software, manual polar alignment

- Lights: 34 x 90 second exposures (total integration 51 minutes), ISO 800

- Darks: 20

- Bias: 20

- Flats: 20

 

Processing:

- Stacked sub-exposures in DSS

- Loaded stacked TIFF in Astro Pixel Processor - autostretch, crop, rotate 180 degrees (preference), removed light pollution, saved file as TIFF

- Loaded APP processed TIFF in PS - set black point, adjust levels to achieve correct colour balance, lasso galaxy and select inverse, gradient Xterminator, very slight further stretch, from Astronomy tools action set - "make stars smaller" x 4, local contrast enhancement, "make stars smaller" x 2,  adjust vibrance/saturation, denoise using Colormancer noise reduction plugin for PS

 

[Richie092]

What a great result for 51 minutes!! Well Done. I'm working on this at the moment thinking I might need another night on it but I might just have a go with what I’ve got and see if I can get it anywhere near as good as yours. 

[x6gas]

Agree that is fabulous for less than an hour's data with a DSLR... and your 4th DSO too!

Congrats!

[MarkAR]

Excellent image, well done.

[Paul M]

Very nice indeed. I'd be suitably delighted with a result like that.

I'm not geared to frame the whole of M31 in one image. I'd have to go mosaic but I think I'll hone my skills on other subjects before I try that!  

[Frankiej90]

Great image @R1k. Good to know your set up/equipment details too, very useful info for beginners 😀

[R1k]

Thanks for the very kind comments. I will look to add more data to this in the coming weeks. Appreciate the support

[Wyvernp]

Have to chime in and say fantastic image! Again, especially with only 51 mins. It's just behind my house at the moment but I'm looking forward to imaging it when it emerges later this month.

[michael.h.f.wilkinson]

Very nice indeed. The background is still a bit noisy, but that is to be expected. As ever, adding more data should improve that. You could also consider going to a lower ISO value. I have an EOS 80D which has a similar sensor, and I find I tend to get best results at ISO 200. For the older modded 550D I tend to go for ISO 800, but the more modern cameras get better dynamic range at lower ISO values, so less chance of blowing out stars or the cores of bright nebulae

[tomato]

That's a great M31. I note you calibrated and stacked in DSS then moved to APP for onward processing. I'm not knocking DSS but please have a look  at calibrating and stacking in APP, quite a few more options than DSS but the auto settings on the latest version work really well. Its a shame not to use it if you have access to it, it's fine  reputation to date has been built primarily on it's calibration and stacking capabilities.

[michael.h.f.wilkinson]

15 minutes ago, tomato said:

That's a great M31. I note you calibrated and stacked in DSS then moved to APP for onward processing. I'm not knocking DSS but please have a look  at calibrating and stacking in APP, quite a few more options than DSS but the auto settings on the latest version work really well. Its a shame not to use it if you have access to it, it's fine  reputation to date has been built primarily on it's calibration and stacking capabilities.

+1 for stacking in APP, it is much better in my view. I have ditched DSS a while ago, and find APP both more intuitive and much better quality-wise.

 

[ultranova]

Most impressive for the amount of time on it,

some nice colors starting to pop through to.

Plus no guiding was used,  a good job all round I thinks,

If conditions allow always go for as much data as possible, to help smooth out the image 

and get a bit more depth.

well done 

Paul

[FMA]

Amazing results. I started yesterday and only got a white diarrhoea. Im using canon camera too. Ill try with iso 800 and longer exposures as you did. What is dark, bias,flats?

Look my white vomit and be proud of what you did., In fact mine, looks like the doughnut galaxy.... 

[R1k]

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

Very nice indeed. The background is still a bit noisy, but that is to be expected. As ever, adding more data should improve that. You could also consider going to a lower ISO value. I have an EOS 80D which has a similar sensor, and I find I tend to get best results at ISO 200. For the older modded 550D I tend to go for ISO 800, but the more modern cameras get better dynamic range at lower ISO values, so less chance of blowing out stars or the cores of bright nebulae

Thanks michael, I’m still limited by exposure duration as I’m not guiding, would it still be worth going for a lower ISO in this case? I’m not quite familiar with the theory of dynamic range 

[michael.h.f.wilkinson]

15 minutes ago, R1k said:

Thanks michael, I’m still limited by exposure duration as I’m not guiding, would it still be worth going for a lower ISO in this case? I’m not quite familiar with the theory of dynamic range 

Increasing ISO is equivalent to amplifying the signal linearly. It basically controls how many counts of the analog-to-digital converter (ADC) are registered for every electron in the pixel. These electrons stem from actually detected photons (the desired bit) and "dark current" electrons from thermal noise. Basically, if the ADC gives more than one count per electron, it isn't adding any extra information, because amplifies both signal and noise equally. Worse, the maximum signal at which the ADC starts clipping the result goes down. This means the dynamic range (ratio of the maximum to minimum detectable signal) goes down. Thus every camera has a sweet spot in terms of ISO or gain. I used ISO 200 on my Canon EOS 80D at only 30s per sub, and got these results on NEOWISE 

[R1k]

Thanks Michael, that makes a whole lot more sense, appreciate the time you’ve taken to explain this. I will look to add more data to this image in the coming days/weeks at a lower ISO and will update the thread. Will also have a go at stacking in APP. Thanks again

[Wyvernp]

15 hours ago, FMA said:

Amazing results. I started yesterday and only got a white diarrhoea. Im using canon camera too. Ill try with iso 800 and longer exposures as you did. What is dark, bias,flats?

Look my white vomit and be proud of what you did., In fact mine, looks like the doughnut galaxy.... 

This looks like a focus issue. 

[R1k]

On 03/08/2020 at 13:53, tomato said:

That's a great M31. I note you calibrated and stacked in DSS then moved to APP for onward processing. I'm not knocking DSS but please have a look  at calibrating and stacking in APP, quite a few more options than DSS but the auto settings on the latest version work really well. Its a shame not to use it if you have access to it, it's fine  reputation to date has been built primarily on it's calibration and stacking capabilities.

Had a quick go and calibrating and stacking in APP then finished off again in PS. Was a fairly similar result. Did mess with the colour balance but here it is. Thanks for the advice, it’s appreciated

[Dan13]

Great image well done, congrats on joining the magical hobby