Wide-field IC1848 in H-alpha

[twade]

Hi everyone,

I'm new to this forum.  I've been using PixInsight for quite some time now.  In fact, I'm part of the Beta-testing team.  Although I still work some with film, I finally broke down and got a CCD imager.  Here's the "first" test image using the FLI ProLine 16803:

1600x1280:
   http://tinyurl.com/yw7ona
2400x1920:
   http://tinyurl.com/2f3jdd

This is a combination of four 30 minute exposures using a Pentax 67 300mm lens shot wide-open at F/4.0.  It was taken during the October Full Moon.  It's amazing what can be done with narrowband filters during New Moon.  The noise was reduced using the following workflow:

1. Remove first wavelet layer using ATrousWaveletTransform,
2. Remove small-scale noise with ACDNR, and
3. Remove medium-scale noise with ACDNR plus luminance mask.

Wade

[Juan Conejero]

Hi Wade! Welcome to PixInsight Forum!

A fantastic image, and a superb noise reduction too.

It is incredible to see images like this one acquired during Full Moon. The resolution and the dynamic range are impressive. Quite different from film, isn't it  :wink:

Did you apply any synthetic flat fielding, or the "natural" flat fields did all the job? I guess that with your skies and a narrowband filter, you must have no sky gradient issues at all.

Something that would improve this image a lot is HDRWaveletTransform. However it must be used with care to avoid excessive compression of the dynamic range.

Another thing that you might want to try is the new iterative stretching script that David Serrano is developing with the help of some members of this forum, based on an original idea of Carlos Sonnenstein. Basically, it applies a histogram stretching procedure in multiple steps, generating an optimized luminance mask at each step. You can see it on this thread. It's a Spanish thread, but you'll have no problems in trying out the script, whose latest version (0.6) is here.

[twade]

A fantastic image, and a superb noise reduction too.

Thanks!  It took quite a few iterations of ACDNR using Previews to get it right, but the result is well worth the effort.

It is incredible to see images like this one acquired during Full Moon. The resolution and the dynamic range are impressive. Quite different from film, isn't it.

It is still hard for me to believe such a deep image is possible during Full Moon.  It's definitely amazing what you can do with a narrowband filter.

Did you apply any synthetic flat fielding, or the "natural" flat fields did all the job? I guess that with your skies and a narrowband filter, you must have no sky gradient issues at all.

The "natural" flat field was all it took.  With a window of only 6nm, the h-alpha filter blocked out all the light pollution from Pendleton (i.e. I did this from my backyard), and the light from the Moon.

Something that would improve this image a lot is HDRWaveletTransform. However it must be used with care to avoid excessive compression of the dynamic range.

I do have a version of the image using HDRWaveletTransform.  Since it was my first attempt, the processing is a little over the top.  I plan on combining the "natural" and enhanced version to see what happens. Here's a link to the HDR image:

http://tinyurl.com/2uv8ag

Another thing that you might want to try is the new iterative stretching script that David Serrano is developing with the help of some members of this forum, based on an original idea of Carlos Sonnenstein.

I'll definitely give it a try.

I look forward to improving my processing skills with all the experts in this forum.  PixInsight ROCKS!!!

Wade

[Jordi Gallego]

Hi Wade,

very nice image indeed, congratulations! :wink:

Regarding your new Finger Lakes CCD camera, may I ask you (at risk of being a little bit off-topic on this forum :? ) your impressions about it? :wink:

best regards
Jordi

[twade]

Jordi,

very nice image indeed, congratulations!

Thanks!

Regarding your new Finger Lakes CCD camera, may I ask you your impressions about it?

It's a pretty awesome camera.  It's very well made.  It easily cools to 50C below ambient.  The images are almost noise free at -25C.  I had a problem calibrating mine when I first received it.  I returned it to FLI.  They fixed a bad electrical component, and I had it back in my hands within 10 days.  I highly recommend it.

Wade

[Jordi Gallego]

Thank you Wade! :wink:

Regards
Jordi