Lagoon crop

[gregbradley]

Here is a crop out of the Lagoon and Trifid image.

Gee I love this AP telescope. It is unbelievably sharp.

Also this camera has 100,000 electron well depth and it shows with the core of the Lagoon not overexposed whereas the STL would have shown that as overexposed for sure.

http://upload.pbase.com/image/99964047

Greg.

[Bassnut]

mm, asking for trouble with a crop Greg, yes the view is impressive, but wonky guiding is starting to show up, and the level is a bit too high on the histogram (have a look).

[jase]

I'm not sure Greg. Are you sure the subs are aligned correctly or a few subs didn't have soft focus? There is nice details in the nebulosity, but in some areas the stars appear to have vanished leaving a small ring where they once were. There is an immense quantity of little yellow stars, I've never seen this before. I would have thought they'd be in proportion to the others in a general way.

[gregbradley]

No its really the processing technique that causes that.

Perhaps its better just to eradicate the stars altogether to highlight the nebula.

Greg.

[Bassnut]

LOL thats a Gendler trick, tried it myself, can look cool, I could help you with how to do that (no stars) ;)

[jase]

:lol:
"Dust and Scratches" Style.:D Nasty, but effective.:)

[gregbradley]

Hi Fred,

How did you do it?

I have used the healing tool in the past but its slow and not workable with large numbers of stars.

Greg.[


quote=Bassnut;344359]LOL thats a Gendler trick, tried it myself, can look cool, I could help you with how to do that (no stars) ;)[/quote]

[Bassnut]

Hi Greg

Well, its my standard process to "colour select" stars before stretchng, and manually select stars that are within bright neb areas (that gets selected because they exceed the brightness threshold, it can take a while, but worth it) I might not use it later, but doing it at this stage saves a lot of grief later if you need it, just save the selection as "stars" for later loading. You need to do this before streching, or too much neb gets selected. Then min filter just eliminates all but the brightest stars (if you push it), and the rest you "heal" out (usually a dozen or so). You may have noticed my images arnt too deep, curves gets rid of the annoying dim ones left. As Jase points out, "dust and scratches" filter does a similar job, but use carefully, as it can affect the whole image, I dont use it.

It depends on the cam, but I use select>modify expand 6, feather 4 and then later min filter 1 or 2 (for RGB, to get them same size as HA) or 3/4 if you want to eliminate the smaller stars

[gregbradley]

Thanks for those tips Fred.

I'll try that out next time to select out stars before processing the main image too much.

Greg.