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mountainjoo
14-01-2016, 03:10 PM
Hello, first post.

This is the first image I've put together where I have managed to both polar align and be dew free.

I followed some processing guides for PixInsight, using lots of fancy tools and masks that I'm yet to learn about properly, so I feel the result could be improved upon as I spend more time with the software. If anyone wants to have a go at processing the stacked image I can upload it.

Acquisition details:

Canon 500D
Orion ED80T with field flattener
Orion Atlas Pro
Orion SSAG Pro with 50mm guidescope
BYEOS, PHD2, PixInsight

30*180 @ 400 iso light frames
20 dark frames
30 bias frames

I've also noticed that my stars are not quite as round as I would like towards the left side of the image, could this be as a result of the image sensor not being perpendicular to the light path? My camera adapter is not as secure as I would like, so suspect this might be the case.

Would be great to get some suggestions on how to improve.

Thanks for looking.

LightningNZ
14-01-2016, 03:39 PM
You've gotta be happy with the mountainjoo. Maybe do a mix of exposure lengths to retain detail in the highlights (tighter, colourful stars, etc)?

Doesn't look like you need flats, but I always find them useful - at least to remove dust halos and such. I would use more calibration frames than you have here to reduce random variation. Bias are easy to take (nearly 0 second) you can generate lots of them. I use 100 and it really helps to cut down on the noise level in the final image. Darks and flats I use 50 of each.

I'm really envious of your setup. Having an oversize mount and autoguiding you should be able to get very long exposure subs if you want.

bobbyf
14-01-2016, 03:43 PM
:welcome:

That's a great first image mate :thumbsup:
I personally like a bit more colour in M42 but you've got some great detail in there. Taking shorter exposures for the core and layering them in PI will make it better still.
Well done
Bob

Somnium
14-01-2016, 04:07 PM
Wow, that is a heck of a lot better than my first effort , well done

mountainjoo
14-01-2016, 04:54 PM
I see it is common to put together different length exposures for this target. I decided against it for now but will revisit this idea in the future when I am more comfortable with processing the data.

Thanks for the suggestion re calibration frames, I will definitely up the count in future. I will also include flats for completeness now that I have a light box.

I did want to take longer exposures, but in 240 and 300 second previews the background looked too bright compared to a suggested guideline in a book I have been referencing (guiding was spot on though). I suspect a limitation of light pollution (I am imaging from a northern Sydney suburb).



Thanks Bob. Learning how to layer different length exposures in PI is on the to do list.



Thanks :thumbsup: