I had explored the whole "starless" thing many years ago and have now tinkered with Starnett++ on a few recent images....to see what it might and might not... do for them.
Then I ran Starnet++ over my recent Ha data with a similar field to Andy's post.
I was amazed how the presence of many Bok globules became much clearer plus planetary nebula or two.
I thought "surreal" and "not too shabby after all"
Excellent data to start with, and the star removal worked remarkably well.
One justification might be that the bulk of the visible stars are well in front of the nebulosity, not actually a part of it, and not behind it either, as the dust is relatively opaque. Thus the star removal shows what the nebulosity might look like if we were out there, very close to it, with the bulk of the visible stars behind us.
A philosophical thought: if there was a very bright star, burning out to a radius large compared with the seeing, then detail out to that radius would be forever lost, because the information was not in the original photo. To be able to reconstruct a starless image even in principle, we require a very sharp original image, such as you have taken, and stars that are not burned out to any appreciable distance relative to the seeing.
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A philosophical thought: if there was a very bright star, burning out to a radius large compared with the seeing, then detail out to that radius would be forever lost, because the information was not in the original photo. To be able to reconstruct a starless image even in principle, we require a very sharp original image, such as you have taken, and stars that are not burned out to any appreciable distance relative to the seeing.
I think there is some logic to that. I tried various colour images and was confronted with artifact central. Tight h-alpha data worked best for me. That said in the original 4k file, there was clear artifacting from the star removal routine. With a little Gaussian blur and just under 50% web resolution it cleaned up quite nicely.
Quote:
Originally Posted by gregbradley
Remarkable detail. I like it.
Greg.
Thanks Greg. The process has been around for a time
I recall reading about a photoshop method over a decade ago, which was picked up by Fred Vanderhaven who did well at the Malin awards with a "starless" image.
Starnet++ automates the process and certainly works well...but I think you need to pick the right data set for it to enhance the image rather than become a fashion statement.
I've been staring at my starless rendition used to create the colour version just posted, and your details are certainly sharper - (a credit to your optics & skills).
Starless images need to have just the the right subject to work well too, as some certainly look better that others!
I've been staring at my starless rendition used to create the colour version just posted, and your details are certainly sharper - (a credit to your optics & skills).
Starless images need to have just the the right subject to work well too, as some certainly look better that others!
Nice use of the technique
Quote:
Originally Posted by leon
Now that is very nice indeed, looks like a raging fire, well done.
Leon
Thanks gentlemen. I'm not sure I'll be making a habit of starless processing, but in this instance it seemed to work well.
The Alluna does a nice job on H-alpha... often approximating it's theoretical spot sizes of around 5 micron...which to be realistic, even on a good night, is double that, due the typical seeing at sea-level.
That said, there is a filigree structure in the nebulosity of the "starless" version that is masked with the "star" version.
I'm not a fanboy of the process as yet, but now see it can have merit.
The contrast in the starless version of this is fantastic Peter, would love to see a SHO version, there are some tiny knots as you mention that do get obscured by stars.
This starless thing is spreading like a disease....
Fabulous detail Peter, just fabulous. The starless rendition really allows you to see every last knot and twist.
Thanks. BTW I have had my Flu jab
Quote:
Originally Posted by Atmos
The contrast in the starless version of this is fantastic Peter, would love to see a SHO version, there are some tiny knots as you mention that do get obscured by stars.
Ta, but, I don't think I'll do a SHO version.
Andy might do one...and if he does don't forget your sunnies
