1st proper go with ASI 2600: M31

[almcl]

I've given up trying to mount my newly acquired ASI 2600 squarely on the MN190's stock focuser and instead decided to screw it to my Canon 200 mm lens.

As luck would have it a clear night came along, so plonking the modded EQ5 mount down on the sopping wet grass and going through the usual set-up rituals, I managed a couple of hours of images at M31 (unimaginative, or what?)

Given that I am still 'learning' both the camera and APT in CCD mode,  I was moderately surprised at how the subs turned out, although am also having to try different workflows in StarTools and haven't got the stars properly under control yet.  Cropped result below.

Comments and observations welcomed.

48 x 3 minute lights
30 flats
35 bias

[AstroNtinos]

It's a smashing image. I love it.

[Nikolas74]

Have you used any filters? 

[almcl]

Thank you AstroNtinos, much appreciated.

And no, no filters, just the Canon Lens and the camera (and my Bortle 6 suburban sky).

 

[teoria_del_big_bang]

Nice image especially for such a rushed setup and test.

I notice you are using bias frames, Most people on SGL seemed to recommend no Bias frames for the 1600 Mono and just use darks.

Is it a case of you couldn't take any darks so used bias frames instead or is the advice different for the 2600 ?

Sorry if this seems a silly question but just curious.

Steve

 

[almcl]

Not silly questions at all Steve!

I haven't done a dark library yet is one reason but my experience of darks with a DSLR was that they didn't help, even when my home made cooler stabilised the temperature and allowed darks at the same reported EXIF temp as the lights. I've yet to experiment with the bias frames to see if they make a difference either way but at least they were quick and easy to do.  

Then there's also the issue of gain and offset settings.  These were shot at a gain of 100 but opinions vary as to whether this works better than gain 0.  Then there's sub length - haven't got my head around the histogram display in APT's CCD camera screen.  At the moment I can't interpret it! 

So quite a bit of learning still required.

Meantime here's a version with less emphasis on stars (not sure if it improve things though)

  

Edited December 22, 2020 by almcl

[Davey-T]

Nice M31, recently received a ZWO ASI2600MC and been trawling through the conflicting advice on gain / offset and calibration frames, I think it's going to be down to trial and error, offset and gain appear to fill up the bottom of the well depth so why that would be a good idea I've no idea, also read that gain is similar to ISO so turned up and down depending on the brightness of the target.

A lot of advice seems to be from hearsay and just repeated by folk without any personal experience 😄

Dave

Edited December 22, 2020 by Davey-T

[almcl]

3 minutes ago, Davey-T said:

A lot of advice seems to be from heresay and just repeated by folk without any personal experience 😄

Dave

Thanks, Dave.  Ain't that the truth though?  I notice several of our more expert contributors don't always agree with the much repeated 'wisdom'.  Trial and error is still valuable!