NGC 4565, Needle Galaxy, LRGB, 25 Apr & 25 May 2018 (David Dearden)

NGC 4565, Needle Galaxy, LRGB, 25 Apr & 25 May 2018

I haven’t been to the Needle Galaxy in quite a while (looks like my last attempt on it was 5 years ago) so I thought I’d give it a try. There was a large gap between getting the luminance data and the RGB, thanks to weather, a graduation, and the position of the Moon (in fact I had quite a lot of moonlight for most of this). I also had a lot of trouble with vignetting and a dust spot in the luminance; apparently my luminance flats need to be redone. I also had a version with weird (nearly no) color from the RGB; I must have done something wrong like loading the wrong data into the color channels, but when I redid it it came out looking the way I expected. Nevertheless, I did better than I did 5 years ago.

Date: 25 Apr, 25 May 2018

Subject: NGC 4565, Needle Galaxy

Scope: AT8IN+High Point Scientific Coma Corrector

Filters: ZWO 31 mm diameter unmounted L, R, G, B

Mount: EQ-6 (EQMOD 2.000j)+PEC

Guiding: Orion Thin Off-axis Guider + DSI Ic +PHD 2.6.4.dev10 (Win 10 ASCOM)

Camera: ASI1600MM-Cool, -20 °C, Gain 139 Offset 21

Acquisition: Sequence Generator Pro 3.0.1.0

Exposure: 79x180 L, 15x180 R, 15x180 G, 19x180 B

Stacking: Deep Sky Stacker 4.1.1 (64-bit) dark+flat+bias, κ-σ stacking with κ = 1.5.

Processing: StarTools 1.4.332: Did RGB combination using Annie’s Astro Actions. Binned 2x2 in StarTools. Used StarTools’ “Wipe”, then stretched RGB in StarTools. Binned the L 2x2 in StarTools, wiped, developed, used HDR optimze, deconvoluted, the used “Track” to denoise. Went with the default colors from StarTools’ color module. Removed pattern noise using Astronomy Tools. Used levels & curves along with some GradientXTerminator to get rid of persistent gradients and dust bunnies in L. Combined L with RGB in Photoshop. Used Astronomy Tools’ deep space & space noise reduction, a little layer masked “less crunchy more fuzzy”, AstroFrame.

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ZWO ASI1600MM/QHY163M

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Status	Basic pending
Started	...
Astrometry.net job	9674323
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