NGC7000

[upahill]

Critique welcomed, first stack of this many 5 min exposures - close to 5 hours on this one, but need to be more selective with my subs I think.

Basic processing in PixInsight following some tutorials and stacked in DSS

Im getting quite a variance in 'score' when stacking. All subs taken the last few nights during practically full moon which hasn't helped. UHC-S filter on Canon 1200d Modded.

Auto-stretching gives two colours, a very red one and the one below which i prefer.

[Allinthehead]

Great result with that moon about. You might be better off imaging clusters with a moon that bright.

[upahill]

Tried again, still 5 hours of subs, but much more selective this time. Also got photometric colour calibration working. Only mod was to reduce some of the stars a bit.

[ollypenrice]

Much better but still a bit thin on colour to my eye. I might also bring in the black point just a tad. It's good though.

Olly

[upahill]

1 hour ago, ollypenrice said:

Much better but still a bit thin on colour to my eye. I might also bring in the black point just a tad. It's good though.

Olly

Thanks Olly, I used the histogram to bring in the black a little which I think looks better as you say - was concerned about the colour alterations as I always find it looks a little too red after.

[ollypenrice]

10 minutes ago, upahill said:

Thanks Olly, I used the histogram to bring in the black a little which I think looks better as you say - was concerned about the colour alterations as I always find it looks a little too red after.

As a predominantly Ha emission nebula it is red so I wouldn't worry about that. While I'd be tempted to try one or two further tweaks they'd be in Photoshop rather than PI which I don't know well. Its a fine result 'as is' though.

Olly

[rockinrome]

Really interested in this. I too recently imaged this with the same camera, but unmodded using CLS clip-in.
Could you tell me what ISO you used please? - I recently found a site that said that (for astro photography) the best ISO was 800 - but could push to 1600 I guess.

Thanks in advance.

 

[upahill]

I used 1600. With dithering the noise was mostly erradicated during stacking anyway, along with the banding which was quite bad in this camera. I had read that the difference in noise between 1600 and 800 was negligible so opted for the higher sensitivity. I have a Baader UHC-S filter in the t-ring.