YALTI - my take on M76

[wimvb]

It seems that there are as many variations of this little object as there are astrophotographers tackling it. Had a discussion with Göran in his M76 thread about the colours of this nebula.

This is from Ha, R, V and B data from the Liverpool telescope. There is plenty of data, so I only selected one single image exposure time per channel (but approximately 30 - 40 subs per channel).

The object has a very bright core and very faint detail further away. HDRwavelet transform was used to tame the dynamic range.

In retrospect, I have overdone the deringing during deconvolution, and paid for that with rather soft stars.

(The link leads to an album with this image in various sizes)

[gorann]

Wim,

Looks very nice and as you say yet another take on it. I see that you now suppressed the green and also saved the core, and you have a very nice natural look in the colours.

Yours is much softer than mine and Paddy's. Largely that could of course be sharpening - I assume you have not done much of that yet. You blame the softness on "deringing" which is a PI term so I do not know what it is (yes I have downloaded it but not yet used it). However, you used 30-40 subs per channel, all being 120 s, which is about the same number of subs that I used although I downloaded everything I could find between 60 and 120 s, but then had to throw out quite a lot of them due to eggy stars or poor focusing (seems like every exposure at LT gets saved). Did you check the subs before you stacked them or could it be that the softness is due to poor subs sneaking in? My reasoning for also including 60 and 90 s subs was not only to get more data but also an expectation that it would improve the dynamic range of the data (but I may be wrong there).

I made a 50:50 mix of our images of the nebula (kept my star field since you were not totally happy with your stars). Does not look bad at all in my humble opinion. Got a quite "natural" and yet crispy look.

Not only are the nights for us up here in Sweden too bright for anything but playing with data - now it is snowing!

Edited April 24, 2017 by gorann