M51 LRGB A QHY183M first light in varying stages. (Pat Rodgers)

M51 LRGB A QHY183M first light in varying stages.

My first venture into CMOS imaging. Strange getting used to just 60 second subs. I quickly learnt not to dither every frame as guiding gets rough very quickly. Also with this camera my HFR readings for focus seem very high to me ranging from 4.92 at best to 6.13 at it's worst, all 1x1 bining. I'm in the period of year where I have no Astro dark only a few hours of nautical darkness, so this could be a reason for the higher HFR readings. The back focus could be another cause, the 55mm recommended to my coma corrector, was achieved using an 8mm spacer. I have tried an 8mm, 9mm and a 7mm but the 1mm difference either way could still be too far allowing for my 2mm thick filters. I've read you have to allow for a third of the thickness of your filters to get the correct back focus, so I'm 0.33mm out either way. I settled on the 7mm as the stars were better near the edges.

Image A: just 12 minutes in each channel plus 1 hour of 300s Ha subs. All 10 gain 30 offset.

B

Description: Up to 31 minutes per channel LRGB. A tad more colour. These two nights were with different spacers which altered the cameras orientation from 90 degrees to 138, amazing what 1mm can do.

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E

Description: Now 43minutes per channel LRGB. The 7mm spacer is attached now which gave a new orientation of 355 degrees? Hence another crop. better colours now.

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F

Description: Now 60 minutes per channel RGB and 132 minutes of Lum. If you have a QHY183 I would like to know the HFR you get during your focus routines. Any advice on this new venture also gladly welcomed.

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H

Description: Just the frames taken with the 7mm spacer.

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I

Description: Added some more RGB 15 minutes each and Lum, a set of 40s and 120s. These were so I could use the Gradient HDR Composition tool in PI, which really brings out the faint stuff like IFN unfortunately it also does a grand job of bringing back the hidden dust bunnies too! A good experiment though.

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J

Description: This is a normal HDR composition version with the extra data added.

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K

Description: Added my 9 hours of 2016 data, taken with the Atik 314l, to this 2019 data. More as an experiment using different resolutions and combining them. I used a star map to register the sets and processed from scratch using RC Astro's gizmo's and a GHS stretch.This image was drizzled using the NSG script too. I was pleased with the result.

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Fast Newtonians
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Status	Advanced success
Started	...
Astrometry.net job	4589247
PixInsight job	4Q6D9HBZ1T60I9JD1UPD7SAAIB6YXESA
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	13h29m46s.260
RA (top/left)	13h27m20s.506
RA (top/right)	13h32m28s.612
RA (bottom/right)	13h32m13s.360
RA (bottom/left)	13h27m01s.781

Dec (center)	+47°11′38″.43
Dec (top/left)	+46°51′22″.99
Dec (top/right)	+46°55′33″.90
Dec (bottom/right)	+47°31′42″.25
Dec (bottom/left)	+47°27′28″.87

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