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Narrowband

California Nebula under moonlit skies


frugal

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First attempt at imaging in a while. Probably not a good idea to try this with an unmodified DSLR, but I figured I would give it a go. Only 10x300s subs before the moisture levels really started to rise and everything just became soggy. Lots of problems with guiding as well, 8 out of the 10 had some kind of guidance error show up in the frame (fortunately they were straight lines out and bak in one of the cardinal directions so they mostly got cleared up in stacking). Final image is horribly noisy due to the poor quality of the starting frames, but I am at least back in the saddle again. Someone remind me where PixInsight put the "Silk Purse from Sows Ear" function, I seem to have lost it ;)

33470068745_4cf1255b6d_c.jpgNGC1499_CaliforniaNebula 

To give you an example of the frames I had to work with:

33086533510_41ddf2b95c_c.jpgngc1499-Light-ISO800-300sec-frame3_16C 

Lights: 10x300s @ ISO800; Darks: 112; Bias: 489; Flats: 35

Scope: Skywatcher ED80-DS Pro

Camera: Canon D60 (unmodified)

Mount: SkyWatcher AZ-EQ6 GT

Guiding: Skywatcher ST-80 and Lodestar X2 using PHD

Processing: PixInsight

 

I tried to move from ISO400 to ISO800 as I read that it helps with the horrible banding from the Canon camera, however now I end up with bright stars blowing out ;(

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Very good effort considering the conditions.

As you have PI go to  script > utilities > Canon banding reduction, (you may have to alter the parameters slightly) it does a great job of removing even the worst banding.

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8 minutes ago, MARS1960 said:

Very good effort considering the conditions.

As you have PI go to  script > utilities > Canon banding reduction, (you may have to alter the parameters slightly) it does a great job of removing even the worst banding.

I make extensive use of that script when I have a bad image, but sometimes the image defeats the script. For example, this stack of 41x30 second subs has horrible banding that does not appear in any of the individual subs, or the bias/dark frames, and defeated all of my attempts at cleaning it up. Fortunately I only needed the core for HDR processing with some longer duration subs.

33346058961_c23513dd20_c.jpgM42_0030s_Color

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42 minutes ago, Nova2000 said:

Nice shot of the California nebula under the given situation. Do you have a single sub with the background extracted? 

Here is the same single sub, but calibrated (Darks, Bias, Flats), Background Neutralisation, and a simple stretch to make it non linear (puts the peak of the histogram at 25%).

33347470761_5fb7ca4d24_c.jpgngc1499_Light_ISO800_300sec_frame3_16C_c_RGB_VNG

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The Nebula is starting to reveal itself--nice FOV.  I know all to well the conditions you face.  If it wasn't for narrowband I would probably have long ago beat my rig into smithereens.

Rodd

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1 hour ago, Rodd said:

 If it wasn't for narrowband I would probably have long ago beat my rig into smithereens.

I keep putting various combinations of CCDs and filters into the FLO shopping basket, in the hope that one time it will magically become affordable; then sighing and taking it all back out again.

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5 minutes ago, frugal said:

I keep putting various combinations of CCDs and filters into the FLO shopping basket, in the hope that one time it will magically become affordable; then sighing and taking it all back out again.

I know that feeling too!

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