Posts Made By: Jim Thommes

Ralph,
Cool image - nice rich color.

Nice image Dan,

Your processing has shown crip detail around the bubble itself. Any special processing?

Nice image. But I have to tell you it spooked me...

At first I didn't see the face at all and then - pop - all of a sudden I see it looking right back at me. Like I'm being watched.

Hi Greg,
Nice image. You have captured features well without burning out the bright areas.

I would have expected to see a little more red in the nebulosity toward the right of the image (away from the blue reflection portions). did the processing suppress red by any chance?

Thanks for the comments everyone..

dan kowall said:

....

I have seen some images of M4 that show some blue stars, such as Jim Misti's:
http://www.mistisoftware.com/astronomy/Clusters_m4.htm
You might be able to increase your blue saturation a touch.
Have you tried shooting a glob with unbinned RGB? I find the color easier to process that way, and it doesn't seem to affect the depth of the image.
I liked the M4 links to the mouse-over and other images on your site. The wide field views give us a good sense of M4's neighborhood.
My regards,

dan

Dan,
I saw Jim Misti's image. I believe he has deeper saturation across the whole pallett. And certainly the blue comes out more noticeably. I could go back and touch the blue, but I have been trying to work on the color calibration and extinction effects into images - I think there is a lot of ways color error can come in though. My first impulse would be to see what tweaking saturation does before adjusting balance. I do usually try to balance a "black" point while keeping midrange and white point unchanged (Sampler tools in PS) - I try not to stray too much beyond that.

I have tried unbinned color before (on a cluster as I recall). I will sheepishly admit it was unintentional (a senior moment while exposing). I believe it was M48:

http://jthommes.com/Astro/M48.htm

Other than not needing to resize, I don't think I noticed a difference in processing (of course, I wasn't looking for one at the time). Do you think there is a potential difference in image quality? Seems like a increased investment in exposure time.

Vince,
Really nice images given your conditions. But it is amazing what can be done in wide field and Ha under poor conditions. Had you not mentioned the conditions, I would not have guessed from the images!

I really like the field and framing of your Propeller, I have seen it done in a narrower field and I had done it narrower as well. Seeing your image makes me want to go back to this object again with this broader perspective.

Dan,
OK, now I see the point in unbinned RGB's - you then don't use (or need) a luminance. Your detail remains at the best resolution your camera has and the hue shifts you can get with a luminance processing are avoided. The trade off as mentioned is the longer exposure time, but now I see the benefits, thanks.

Matt,
Thanks for the comment on the image. Yes, I do tend to clip the black level a bit with clusters - particularly if I don't expect anything faint or fuzzy in the frame.

All,
Looks like i am on Holiday for a week or so. I will check back in when I get back.

Hi Dennis,
Nice image on the comet.

So my theory is that the comet's visual mag comes from the total its disperse cometary cloud. It will have an associated surface brightness which is likely low and more difficult to detect visually. Where as the star as a point source at 8.4 would come through as a beakon in a 14 inch.

Just to give an upper bracket for this thread, I use the Astronomik 13nm.

I would like to try something narrower at some time for comparison.

Tom,
Really nice capture. I like the "Stars Corrected" version best.

I was just glancing through the thread, but didn't catch the RBG filters you are using. Which are they? You seem to have gotten the internal Teal color pretty close - did you have to adjust for that color, or did it come from calibrated processing?