Cocoon (reprocessed starfield)

[alan4908]

Following on from my recent Cocoon I thought I would have another go.  Apart from the fact that I had inadvertently black clipped the entire image ...... I really liked the Cocoon result but I the more I looked at the image the less I liked the starfield. So, in this attempt,  I decided to see if I could improve the starfield.  

One defect that I noticed was that my stars did not display a uniform colour, on further investigation I discovered that my average FWHM in each of the RGB channels varied quite a bit which I presume is a consequence of the inability of my scope to focus the RGB channels to the same point. So, I decided to compensate by deconvolving each channel separately to obtain approximately the same FWHM in each channel. I then re-registered the deconvolved images and created RGB starfield. The result was a more uniform star colour. 

Alan

 

Lights: Ha 5 x 1800s, L: 19: R:16;G:13;B:15 x 600s. DARKS: 30; FLATS: 40; BIAS: 100 all at -20C. 

[johnrt]

Hi Alan,

I think that is a huge improvement, you have the dust lane nicely there & a really nice level for your background, dark, but not too dark. Excellent!

[alan4908]

Thanks John. I have to say, this starfield was interesting to process and I've learned quite a lot in the process. 

Alan

[wimvb]

I agree, it looks great. This image works much better as the widefield you show here. Also, great star colour.

[alan4908]

Thanks for the comment Wim.

Your point on the widefield perspective is interesting.  I think I have a natural tenancy to overdo close crops since I always like to maximize the image detail of the main subject, however, the stars within the star field can get quite large and unattractive if this technique is overused.

Alan 

[wimvb]

Yes, sometimes stars can intrude and take over the image. Keeping stars under control will be important, but as long as the nebulae remain the main subject in your image, a widefield can lift it.

[PatrickGilliland]

Nice image and all objects look in order, stars can be a pain though can't they :).  That said after my first year of processing with far too much star reduction i decided that they should be there and practiced their inclusion rather than exclusion.  I focused on managing the size early on rather than adjusting/reducing later.  All sounds obvious enough but is actually harder to do.  This image has a nice balance though i would not be worried about allowing more stars if available, this also helps contrast the dust lanes better.

Paddy

[alan4908]

1 hour ago, PatrickGilliland said:

 

Nice image and all objects look in order, stars can be a pain though can't they :).  That said after my first year of processing with far too much star reduction i decided that they should be there and practiced their inclusion rather than exclusion.  I focused on managing the size early on rather than adjusting/reducing later.  All sounds obvious enough but is actually harder to do.  This image has a nice balance though i would not be worried about allowing more stars if available, this also helps contrast the dust lanes better.

Paddy

 

Thanks for the comments Paddy -  I do find starfields challenging, particularly when they are embedded within nebulosity !

Alan