A bit of Makarians Chain really.
No Darks or Bias, only Flats which gave a much better result. Go figure. Sigma stacked and processed in DeepSkyStacker only. Tried StarTools for days using differsnt DSS outputs but it all went very pink! Star Tools recommends a straight median stack with no calibration or colour correction as input. Either way it didn't like this image.
5.5hrs @ISO1600 Canon 1100D defiltered with LPS-D1 light pollution filter on LX90 8" with Baader Alan Gee II Telecompressor and Brightstar OAG/QHY5L-II mono for guiding with PHD2.
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/normal_M86_Makarian_DSSFlatsOnly2.jpg) (http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/M86_Makarian_DSSFlatsOnly2.jpg)
Very nice Duncan. I don't always use darks and Bias, just flats. If I have darks I'll use them but I've found over the last few years that sometimes Bias completely messes up the image and it's better without.
The centre of the image looks brighter than the corners, it doesn't look on first impression that flats were taken.
Carole
Very nice Dunc - looking good - John
Quote from: Carole on Apr 19, 2016, 09:27:19
The centre of the image looks brighter than the corners, it doesn't look on first impression that flats were taken.
That is a possibility and I've just labelled the output incorrectly! Mind you I often find my flats undercorrect using DSS, I've tried sky flats, ELP flats and various exposures but it seems a bit random.
I haven't used DSS for quite a long time, except when i go back and do a bit of DSLR imaging as I haven't fathomed out how to stack colour in Astroart, but I do recall having had a few strange results with flats (and Bias) in DSS, but more to do with the dust bunnies which I think it was overcompensating for, and after stacking the dust bunnies came out looking like craters!!!!!
DSS is great for free software, but I think it can be a bit erratic from time to time. Have you ever tried any other stacking software, some people swear by Nebulosity, I have tried it but find it a bit cumbersome having to do a lot of it manually, but seems to produce good results.
I am at work now and on the screen here I can't see any sign of vignetting on the work PC.
Carole
Excellent - you've got some good colour in there.
Mark
Good work Duncan!
Obviously it's been a difficult image to process Duncan but the result has come out very well.
Robert
Thanks all.
It's got a lot of detail and some colour but the old comma splurge has reared it's head again. I need to play around with the reducer/flattener spacing again. And I wish I could work out why I can't process the stack in StarTools. Maybe time to get something else.