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Kev11
10-08-2019, 08:58 PM
In response to Alex’s challenge I hereby submit some images I am not unpleased with.
All with Skywatcher 200mm f5 reflector on HEQ5Pro mount in my home-made observatory.
Canon 1100D unmodified at prime focus.
Generally 5 or 10 30 sec subs at ISO 1600.
Stacked with DSS and minimal post-processing, mostly aligning RGB curves.
I don’t have a problem with light pollution, nearest urban areas being well below the horizon; main limitation is availability of cloud-free moonless nights (I am past playing around in the early hours of the morning as we used to do 60 years ago – even if Her Indoors would allow it!).
I aim to have target objects at 50 degrees elevation or better and on good nights, particularly in a dry winter like the current drought, seeing and transparency can be almost excellent.

Kevin

Startrek
10-08-2019, 10:34 PM
Nice images Kevin, I especially like the Jewel Box although at 30sec subs you either have some tracking issues , some coma or your polar alignment is out a bit as your stars are not particularly round in most images for such short subs
Have you guided before ?
Have or do you use a coma corrector ?
I use a 6” f6 and 8” F5 newt and an unmodded DSLR for AP , can’t do without my Baader coma corrector and I guide on all exposures 30 sec to 5 minutes

xelasnave
11-08-2019, 12:27 AM
Thank you Kevin for sharing your images.
They are pretty decent and I must say my favorite is Omega C...top effort.
Keep them coming.
alex

Kev11
11-08-2019, 08:47 AM
Thanks, Alex. I have a particular interest in Globulas and will put some more up shortly.



Thanks for the comments, Martin. The polar alignment should be pretty good as it gave me a lot of trouble to get right when I first set up the mount on the permanent pier. In any case I always do a 2 star alignment and a PEC on the star I use for focussng with the Bahtinov. I think the problem is the camera not being square on and also wobble both due to a slightly loose focusser element that I need to sort out.


I will take up your suggestion of a coma corrector.


Cheers
Kevin

Sunfish
12-08-2019, 01:47 PM
Like the jewel box also. Very crisp and colourful. Perhaps there was high cloud on the other shots.

Kev11
13-08-2019, 08:11 AM
Thanks, Ray. No cloud, contrast lacking probably due to my inexperienced playing around with DSS adjustments. Should have explained earlier that these images are cropped Jpegs and overreduced to send to IIS.
Also didn't respond to Martin's suggestion about tracking. My HEQ5Pro tracks up to 75 minutes without any discernible drift provided I align carefully each night (is on a permanent pier).
Kevin

Decimus
13-08-2019, 08:59 PM
Nice shots, Kevin, but your Omega Centauri is particularly impressive - lots of well resolved detail. I have used DSS a few times and ended up with a dark green mess and nothing really visible,. I don't get it at all so I don't use it. Many of these software writers, clever a s they are, seem to struggle with writing simple, BRIEF, step by step instructions for those of us (like me) who struggle with the technical lingo/jargon.Sorry about my rant here - wrong place for it :D

Well done.