Differences between HARVB-AIP, SHO-AIP, NBRGBCombination and how to use?

[jerryyyyy]

Jerry,

Any issues if I post using Google Drive?  I have my own website that I built with Dreamweaver so I don't use astrobin.

Best,

Jim

No issues.  Here is SH2 112... clear skys last night and sucked in 5x1800s of H-alpha and processed both ways this am... I am learning to like the fire engine red approach....

http://www.astrobin.com/196212/B/

PS  If anyone has any suggestions for Sharpless2 items to image I am open for suggestions and not quite sure what would be next... 112, 115 and 116 are nearby each other am make scheduling easy. 

[jerryyyyy]

Since I'm at it one more attempt.  This time using NBRGB combo but using the synthetic luminance for ha. 

http://www.astrobin.com/194889/E/

Hi, I looked at all these this AM after I put up SH2 112 and we are in the same boat I think. 

The good news is that we have a huge amount of flexibility with these two scripts in PI.  I am sure I could generate fire engine red given enough time with the AIP H-alpha script.  The AIP SHO script has more control.  Wonder if I could adapt it for the H-alpha blending.

[jkmorse]

OK, got out of the dark ages and finally joined Astrobin.  Will post there when I get NGC7000 processed this week.

Best,

Jim

[jkmorse]

Jerry and others,

I am curious why you would not use all three NB colors at full value to create the SynLum image.  That's what you do in an RGB image and I would think that you would want the Lum to capture the nuances from all the NB range.

Thanks,

Jim

[jerryyyyy]

The L will not pick up anything.... with the Sh2 objects I stopped shooting L and just get 6 each of RGB to color the stars right.  All the signal there is in H-alpha with a touch in the R channel.  You need narrow band.  If you look at the AIP script it has two different ways to construct a synthetic L and then it probably uses it they way you suggest.  No expert on the inner workings of these scripts....

I am on vacation fishing will play with this a little.  Another big issue is to not bloat the stars when you stretch the narrow band.  I am not sure the scripts use any masks or other tricks to alleviate this problem. 

Above my uneducated opinions....

[akulapanam]

I'm in favor of the synthlum approach especially where you have reflection and emission nebulas in the same frame.

[jkmorse]

Hey guys,

I did a full blown test comparing my traditional method with SHO on NGC7000.  I found the results so interesting that I started a new post.  You can find it here:

http://pixinsight.com/forum/index.php?topic=8761.0

Best,

Jim