Markarian's Chain LRGB

[chartram]

Good day,

Had clear and relatively moonless nights here in Central Georgia, didn't want to let them go to waste. This target needs no introduction, it is a beautiful chain of mostly gold/brown elliptical galaxies that trails southward from Coma Berenices into Virgo. The image is not cropped, really like the way it filled the FOV.

One of my "bucket list" items is to visit the Griffith Observatory and see "The Big Picture", which includes this target.

Markarian's Chain in LRGB
Imaged March 7th and March 8th, 2021 from my back yard in Kathleen, GA, an Orange Zone

80x300s Luminance
50x180s RGB (2x2 bin)
14hrs, 10mins total

Scope: Orion ED80 (F/7.5) with Hotech SCA/FF
Camera: ZWO ASI1600MM Pro @-20C, gain 75
Filters: Baader 1.25" LRGB
Resolution: 1.31"/px
Mount: Skywatcher NEQ6 Pro
Capture: SGP
Processing: PixInsight



Right click the image for closer view in a new tab.

Comments/critiques welcome and appreciated. Thanks for looking!

Mike

[KathyNS]

Very nice!

[AstroBee]

Beautiful image Mike.

I'm curious about your choice of gain at 75 though. I've got the very first version of the 1600mm cooled camera so I don't know if the gain structure has changed on the newer models but I was under the impression that unity gain was 139.
Any benefits of running at a lower gain like 75? Also, according to Robin Glover of SharpCap fame, there's no significant gain in image quality by running at a temp lower than -10°. Running at -20° just requires more power which can be important in the field when using batteries but not really an issue if you are near main power.

[TheButcher]

Great Image!

[chartram]

Beautiful image Mike.

I'm curious about your choice of gain at 75 though. I've got the very first version of the 1600mm cooled camera so I don't know if the gain structure has changed on the newer models but I was under the impression that unity gain was 139.
Any benefits of running at a lower gain like 75? Also, according to Robin Glover of SharpCap fame, there's no significant gain in image quality by running at a temp lower than -10°. Running at -20° just requires more power which can be important in the field when using batteries but not really an issue if you are near main power.

Thank you!

I read early on that 75 is the ‘sweet spot’ for dynamic range with the 1600. So when I first got it, I basically did a ‘set and forget’ and have not messed with it since. Also, any change in gain would drive a change to my dark library, which is another turnoff. There are definitely advantages to shooting at higher gain levels, but also trade offs in subtle light/dark transitions and brightness of objects in relation to one another. So I guess my personal choice was to invest more time per target for good dynamic range vs. less time at higher gain for more signal. The key word is choice, I have seen some OUTSTANDING images shot at unity gain and beyond.

As for temperature, -20 is my normal winter setting, -10 or -15 for the rare summer outing. I use a pretty stout deep cycle battery that usually can get me through 24+ hours with everything running before requiring recharge. On a cold night, the TEC runs at about 30% to keep it at -20. It’s a fantastic system on these cameras. Not sure what the point of diminishing returns is, but -20 seems to work. In the end, I think you hit it on the head. It’s all personal choice.

Mike

[Makuser]

Hi Mike. A beautiful Markarian's Chain image in LRGB light. And you caught a bucket full of great DSO's too. M84, M86, M87, M89, M90, and several others show up quite well. Thanks for sharing this wonderful capture with us Mike, and keep up the great work.

[MariusD69]

Wonderful image! Well done, Mike!!

[OzEclipse]

Beautiful capture of one of my favourite parts of the sky.
Had the 18" pointed that way on Saturday night and tried collecting some data with an 8"f6.4 of the chain last night. Mine will only cover the bottom right quarter of your image.

Congratulations on a beautiful image.

[messier 111]

magnificent shot , thx .

[BABOafrica]

That is a beautiful capture of one of my favorites and you did it so perfectly.

The EYES came out especially well in the detail and color.

BABO

[Gordon]

Congratulations Mike on having your image selected as todays TSS APOD!!

app.php/article/3-10-2021-tss-astrophot ... of-the-day

[Ruud]

Definitely an APOD. Well done and congrats to you, Mike!

[helicon]

Congrats Mike on the APOD! Fantastic image.

[Jockinireland]

Thats a lovely image, nicely framed amd well processed

[starfield]

Love all the faint fuzzies you've captured here. Congrats on the APOD

[jrkirkham]

I love that picture

[ram]

Stunning! I love galaxy fields - never attempted them myself yet so living vicariously -- looks like you got some good time in for this...

[Astrovetteman]

Beautiful job on this Mike!! Congrats on the APOD!!
Great Image!!
Tom