Gettin' there

[Pete]

Saturday, 28 Nov 2020

This afternoon ran a comprehensive set of darks at -15C. Clouds cleared precisely at 18:30 as forecast.

Tonight’s objectives are to improve my handling of darks and flats, and to investigate severe banding experienced the last two nights out.

NGC 7380 – The Wizard Nebula – discovered by Carolyn Herschel in 1787. Listed as 7.2 magnitude. Runs made with 5 min exposures, -15C cooling, gain of 200, binned 4X. This image 11 X 5 minutes.

I’m trying to keep things simple and this is as good as I need to get. But the learning curve still rises in front of me and this wasn’t simple at all.

There was a lot of experimentation. Discovered a fine control histogram in the SharpCap software thru a YouTube SharpCap tutorial. Makes a world of difference when viewing stacking as it allows precision stretching. The individual images are have basket weave banding when loaded or stacked into ImagesPlus, but the stacked FITs image is clean when loaded into IP.

The computer seemed to shut off midway thru the 7380 imaging. Discovered thru YouTube that the individual frames saved could be processed in SharpCap even though they were unusable in IP. Used for this 7380

The darks are working well. Thought the flats weren’t working but even with dark corners on the left and white corners on the right there were no dust motes and all corners weren’t black. So flats are working. It’s the flats capture work that needs redoing per the directions that Robin sent me.

Conclusions & lessons learned:

Achieved a pretty decent image. Finally getting close.

Based upon the uncropped 7380 my FOV is 32.5’ X 22’ , my actual f ratio with the f/6.3 focal reducer field flattener placed to fully illuminate the large chip is f/8.4, and my working focal length with the FR is 2970mm.

[Bruce D]

Pete I'd say you've made a quantum leap forward, that looks like a darn fine image to me!

My camera arrives a week from tomorrow...

[menardre]

Pete

Outstanding image of the Wizard Nebula. Colors are fantastic.

I know I would be pleased with your results.

Looking forward to many more great images.

Roger