IC1805--Image Processing Questions and Suggestions

Hello all,

I recently posted a image of M31 which I thought I did a good job on
in processing. I am now in the process of processing my most recent
work, which is IC1805, or the Heart Nebula. I am using a Takahashi
Epsilon 250, Paramount, and STL-11000M. For this image, I have 15
total hours of exposure: 7 hours of Ha (for luminance binned 2x2,
which yes I know was a mistake but I have to deal with it now), and
the rest devided evenly between RGB (also binned 2x2).

Now I have some questions about processing this image. I dont
consider this image finished by any means. I think I may have
overprocessed it, but I am finding it difficult to process this image
because of the wide range of brightnesses th nebula takes since it
occupies almost the entire frame. This makes selections for blurring
and sharpening difficult to determine. I think this image has much
potential, but I believe Ill have to start over with the combined RA,
R, G, and B frames in photoshop.

A few particulars I have questions about:

1)I think the color data has too much noise in the dim nebulosity
areas. Since I am an idiot and accidently binned my Ha Luminance
frame 2x2, will I lose sharpness if I process the RGB for brightness
levels only. I think I tried to bring out sharpness detail in the
color frames too much. So all in all, is it ok to process the Ha
Luminance frame for sharpness and leave the color frames along in
this respect?

2)In trying to get my color balance right, I think I have stretched
out the red data too much. I say this because in some of the darker
areas, there are dim, red stars. I am assuming they are all red in
color because they are brighter in the red channel, and may not even
show up in G and B. Does this explanation seem plausible?

3)The Epsilon 250 seems to have some nasty internal reflections at
short wavelengths. Note the bluish halos around the brighter stars.
Any Epsilon owners know how to process that out? It would normally be
fine in an LRGB image where L is the all spectrum image, but since
the halos dont show up at all in the Ha data, the blending of the Ha
and color makes the halos really stand out and I am not sure if I
like it or not.

4) I also think there might be a slight G gradient in the lower left
corner. Any ideas on how to get rid of that without buying new
software. I originally removed a larger gradient in G using the
NewAstro Gradient remover for CCDSoft.

Anyways let me know of any comments or suggestions and answers to the
above questions. I appreciate it. I just spent so much time imaging
this object, I would love to see this image look stunning. Thank You.

Taylor

Attached Image:

Hi Taylor,

I am afraid I won't be much help to you,my experience combining Ha and RGB is limited to a total of 1 time.The Ha sure can overwhelm the RGB!

Rob Gendler has some good tips on combining Ha data with RGB on his sight,if you have not looked at it already it would be worth a read.

You have a lot of good data! and your image looks good as it is.I'm sure you will be able to improve it though

Jason

Taylor,

I second the suggestion to check out Rob Gendler's tutorial on his site. You've done a great job so far, BTW. Just a bit more tweaking and you'll have a spectacular shot! On the haloes, I don't have a BRC, but I've dealt with those before. I forget what combination of tricks I used to tame some haloes in the past - one thing I did try was shifting the image mode from RGB to Lab mode (in Photoshop), then attacking the haloes in the a or b channel (depending on where they are - I'd split out the channels before doing so). I'd use the Dodge (or is it the Burn?) tool - whichever one either lightens or darkens the halo, as the case may be as well.

HTH,
Eric

Taylor,
I know I'm late to this discussion, but I'll third the suggestion of reading Robert Gendler's article. I also brought up the question of combining Ha with RGB on the PixInsight forum for feedback by the program developers. The concensus was that Ha does not make for a good luminance based on both star size and color effects. Definitely adding Ha to the R seems the way to go. A split of opinions on adding Ha to the L as well. I did a bit of a test with an old image of mine on NGC281. I had to use a combined RGB as my L. I can tell you the difference in color was profound--much better red when I combined the Ha and R than when I used the Ha as the luminance. I didn't really see much difference between that and when also adding Ha to the L for the luminance. But it has convinced me to really treat my Ha and color shots differently. I'll have to post the results on my website soon.
Hope this makes some kind of sense...although I think you already have a wonderful shot!
Larry