Rosette Nebula

[furgle (Adam)]

Just another rosette

**Image:**
* 18x 300s Red
* 25x 300s Green
* 46x 240s Blue
* 68x 360s Hα

Total exposure 13 hours 27 minutes.

Better resolution here

**Hardware:**

* Skywatcher Black Diamond ED80
* SkyWatcher EQ8 Pro Mount
* QSI 683-ws Camera @ -15°C
* Astronomik Deep Sky RGB, 6nm Hα filters
* Starlight Xpress Lodestar X2 Autoguider
* Innovations Foresight On Axis Guider



**Location:**
* Orange zone in Brisbane, Australia. (Bortle 7)



**Software:**
* Planning & camera alignment with The SkyX Pro
* Captured with AstroArt 6
* Guiding with PHD2 + PHD_Dither
* CCDInspector: Image analysis & rejection
* CCDStack 2+: Calibrate, align, stack.
* PixInsight: Deconvolution, denoise, pixelmath combine Hα + blue as luminance, MT star reduction, MMT sharpen, histogram & curves stretch, local histogram equalization, color saturation.

[furgle (Adam)]

Whoops on the date in the image. I only used photoshop for one thing, and still managed to get it wrong.

[Peter Ward]

Great technique and heroic exposure times...but you are making it an arduous task with a modest 80mm aperture and fairly dim target.

Might be time to look at look at a larger instrument? (plus I suspect that scope has a smidge of spherical error judging by the stellar halos)

Nice result just the same.

[furgle (Adam)]

I'm guenuinely curious about what may be a better scope in the 600 and 1000mm focal lengths. My imaging train is quite long so it's hard to find something with enough back-focus. Newts don't seem to be much good since the train is also quite heavy and changes the collimation of the tube. (On axis guider + QSI683ws-8, and an SX-AO if there's room to spare.

[willik (Willik)]

HI Adam 110 Refactor triplet Refractor would be nice with that mount you got
that would not be a problem but your image looks very good to me.
and the xtra money that would not be cheap.
Martin

[Peter Ward]

Originally Posted by furgle

I'm guenuinely curious about what may be a better scope in the 600 and 1000mm focal lengths. My imaging train is quite long so it's hard to find something with enough back-focus. Newts don't seem to be much good since the train is also quite heavy and changes the collimation of the tube. (On axis guider + QSI683ws-8, and an SX-AO if there's room to spare.

Simple physics really...

Going to a modest say 13cm, you gather over 3x more light...so what took you 13 hours on the E80 you will get in under 4, with better resolution to boot.

Not saying you have to...simply something to ponder.

[furgle (Adam)]

Thanks guys. I understand focal ratios, I was more thinking specific scopes. I've looked through OPTs scopes and apart from ones over 10k there's not a lol of non Newtonian scopes lower than f/7