M27 Dumbell Nebula
Posted 18 June 2013 - 12:54 PM
This was collected over my last two clear days in June. it worked out pretty well. I ended up taking 10 each RGB @ 30 sec and around 25 each RGB @ 240sec. Total integration is around 6.7 hours. Processed in PI very lightly. Steps as follows:
Started by doing HDRComposition to remove the 'tails' from my NABG camera's stars. Not a wonderful job, but pretty good. I think I should've done even shorter exposures... the tails that are there were there in a 30sec exposure!
2. DBE (20 pixel, .75 Weight, 10 samples)
3. BackgroundNeutralization (hard to find a 'dark' spot with no stars in this image)
4. Color Calibration (used same spot for the 'dark' and used the grouping of stars in the upper left with structure detection 'on')
5. HistogramTransformation (basic stretching)
6. HDRMultiscaleTransform (5 and 1, only to the luminance and lightness, de-ringing on)
7. TVGDenoise (100 interations, allowed convergence, NO masking) This process is amazing at noise reduction. I didn't have to do ANY masking and it really did a great job at getting rid of the noise. It's my new favorite.
8. HDRMultiscaleTransform (3 and 1, only to the luminance and lightness, de-ringing on)
9. CurvesTransform (to increase the luminance channel and greatly increase the saturation in the stars.
10. Applied a star mask and did another CurvesTransform to just M27 and the brighter stars. (This completed the 'normal' image look)
Questions/criticisms/compliments are appreciated. The last step was due to guys on #astrophotography telling me it was quite saturated enough!
Here is a picture of my original one last year from June:
Thanks for looking,
Posted 18 June 2013 - 01:10 PM
Posted 18 June 2013 - 01:13 PM
Exept for the colors this is a great image. But imo the colors are not quite right. uusally the nebula is Magenta/red and cyan/blue. Yours is much too orange. other than the colors I like your image. Quite some detail and pretty good stars. I think that if you take another look at the colors you'd have a winner.
Posted 19 June 2013 - 09:40 AM
Thanks for the help!
Posted 19 June 2013 - 09:47 AM
Posted 19 June 2013 - 09:37 PM
Posted 20 June 2013 - 07:44 AM
Posted 20 June 2013 - 08:52 PM
Posted 21 June 2013 - 04:44 AM
Posted 21 June 2013 - 06:44 AM
Posted 21 June 2013 - 08:43 AM
Posted 22 June 2013 - 12:27 PM
a: using hue saturation I shifted the whole imaage more to the green. Alos inclreased saturation slightly
b: the adjustment of the colors affected the overall brightness of the image. This was countered with a curves adjustment.
Below my result. Hope this helps you a bit more to sort out this image.
Posted 22 June 2013 - 05:21 PM
My process was very iterative:
1) Color Combine
3) Dynamic Background Extraction (DBE)
4) Color calibration
5) Histogram stretch
6) Dynamic Background Extraction (DBE)
7) HDR Multiscale Transform
8) ACDNR noise reduction
9) Histogram stretch
10) Dynamic Background Extraction (DBE)
Posted 22 June 2013 - 09:55 PM
Posted 29 June 2013 - 09:26 AM
I'd originally set my filter wheel up RGBL and swapped them around the last time I had the camera down. Unfortunately, my laptop had a PS issue and I never changed my software!
ARgh I ended up shooting the 'B' channel for my other images last night before the moon came up. Hopefully, I'll have some correct images later.
Posted 29 June 2013 - 09:32 AM
I'm wondering why you changed away from RGBL? That is a pretty common setup. I have mine as LRGB (after all, that is the way it is often referred to), and found that isn't the "standard" way of setting them up. Still I like them that way.
Posted 29 June 2013 - 09:40 AM
After doing that, the frame that is clearly much brighter than the others is the Green channel (so what was originally labels R).
Anyway, looking at it after the fact, I can well believe that what I have labeled as the Green channel is in fact luminosity.
Posted 29 June 2013 - 10:49 AM
I think I had a momentary lapse of judgement. I dunno why I changed it.
Posted 29 June 2013 - 11:43 AM
Here is what I ended up with. This includes some blends of HA and OIII into the RGB channels and I finally got deconvolution to work.
Posted 29 June 2013 - 12:04 PM
I'm no expert in deconvolution, having only begun using it myself. But I can see from the bullet hole in the bright star that you need to mask of the middle of it/and or fooled with the ringing parameters to prevent it.
Posted 29 June 2013 - 12:29 PM
Here's the Narrowband bi-color version. Pretty legit IMHO. I agree completely with your assessment of the RGB.