M31 Revisited

[Jm1973]

As I've had no good weather lately to get the telescope out, I've gone back to some subs I took a while back. I had previously processed them entirely with GIMP. I was pleased with it as it was my first time stretching an image, but there was a lot of 'haloing' around the image and the core was very bright.

I downloaded the free trial of APP and had another go at it. I used the 'Correct Vignetting' tool (which didn't seem to do an awful lot), and the 'Remove Light Pollution' tool which seemed to work quite well. Then I stretched  with GIMP again. I think the result is a lot better. I am just waiting for clear skies now to get some other footage I can play with.

 

Edited October 4, 2020 by Jm1973

[Tommohawk]

I would say  that's pretty good. I used DSS for ages but have now moved over to APP - it does seem more reliable.

You seem to  have lost some of the blues maybe? Also you have something of a trail that might have happened on one sub only - how many did you take, and do they all show the same trail? Maybe if you post some more details re your kit and settings folks here could make more constructive observations?

As you say  clear skies would help!

Edited October 6, 2020 by Tommohawk

[Jm1973]

11 hours ago, Tommohawk said:

I would say  that's pretty good. I used DSS for ages but have now moved over to APP - it does seem more reliable.

You seem to  have lost some of the blues maybe? Also you have something of a trail that might have happened on one sub only - how many did you take, and do they all show the same trail? Maybe if you post some more details re your kit and settings folks here could make more constructive observations?

As you say  clear skies would help!

Hi. Thanks for the reply.

At the time of taking the subs used in that image my kit consisted of a skywatcher 200p on an eq5 synscan pro goto, with an unmodified d3300 attached directly to the focusser with a T ring. 

A number of the subs have some trailing, one in particular is quite bad. However I think they are not primarily due to tracking issues, as many of them do not have trails at all. I think they are due to me not having an intervalometer, or shutter release, at the time so I had to manually push the button on the camera for each exposure. I think that caused a slight trail on a lot of the images. I may be wrong though.

I took about 100 30-second subs, at iso800.

Since then I've bought a long usb repeater cable, and nikon data cable and downloaded digicamcontrol, so if that was the cause of the trailing it shouldn't happen next time.

Sadly the weather has been terrible the last few weeks, and even though tonight turned  out to be unexpectedly clear, I'd agreed to watch a film with my better half, and didn't even realise the clouds had vacated until it was bedtime. Hopefully the clear weather will continue tomorrow evening.

Clear skies.