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My first DSO with my new scope (Esprit 100ED) taken over a couple of nights this week with a modified 450d. It was stacked with only a little bit of processing in AA6, 42*300s subs, darks, bias and flats all captured using APT. PA was done using Sharpcap Pro and guiding is with a ZWO 60mm guidescope and an ASI224MC. I dither between each sub so don't know whether I should stop using darks, also I need to sort out my guiding as it could be a lot better. My processing skills need to be improved a lot, I'm considering getting Pixinsight, I've seen lots of great pictures using it, how easy/hard is it to learn the basics to get a reasonable result from? Here it is let me know what you think good or bad.
I recieved my new toy on Friday but didn't get time to set it up till Saturday, to my surprise it remained clear, so went to try it out. Everything went so well I polar aligned in no time using Sharpcap. I slewed over to Alkaid and focussing with the Bhatinov mask was a doddle with the very smooth 3" focusser. I use APT and CDC/Ascom to control everything from a laptop next to my mount, I used Goto++ & PlateSolving to move to my target NGC6960 (The Witch's Broom Nebula). PHD2 quickly calibrated and appeared to be guiding very well. I then set APT off capturing 300s subs with a dither after each one. I thought to myself if this is how it's going to be everytime with my new scope this pastime is going to be so easy from now on. I retired inside RDC'd from my other laptop to keep an eye on the progress and relaxed. After about an hour APT started it's automatic Meridian Flip process, that's when everything went pear-shaped, it failed to platesolve it's image and timed out, so I tried forcing it to flip and it just would not platesolve the 30s image it took. I then did a Goto++ on my target, the mount did a flip took the image and platesolved it first time then happily started taking 300s images again. It got to about 01.00 and I was getting tired so I stopped it capturing thinking I'd better go to bed, but then I noticed Cassiopeia had appeared from behind my house which meant M32 would be in view and I wondered what it would look like captured through the Esprit. I slewed round and looked at the sub then did the stupid thing of rotating the focusser to try to get it across the corners of the sensor to capture as much as possible, I took 4 subs, then a few darks and packed everything away. It wasn't until the next day when I took some Bias and Flat frames and tried to process it all that I realised by moving everything I had ruined the flats. We live and learn. Anyway I managed to just stack the 12 lights from before the flip and cropped it with no further processing until I get some more subs. I'm very please with my new scope.
NGC6960 – Witch's Broom Nebula
Really delighted with this one. We had a lovely evening where I could get some great subframes, it was stable and nice and clear for a change.
This is a supernova remnant in the constellation of Cygnus. Its original host star exploded some 5000 - 8000 years ago. It is roughly 1,500 light year away from us.
My first serious go at a narrowband image taken over a few nights from my back garden in not-so-darkest North Staffs
Ha: 30 x 300s
OIII: 28 x 150s
R: 22 x 30s
G: 22 x 30s
B: 22 x 30s
(I also took a whole load of L lights but didn't use them in this versions - still feeling my way in to NB imaging)
RGB lights used for star colours only.
Calibration: Bias and flats, no darks (dithering)
Ha used for Luminace and Red channel
OIII used for Blue and Green channels
Equipment list in sig
Had another go at my 2.8 h of data on this nebula from 2015 and 2016, trying to control the star field better. One reason was that I just invested 50 dollars in the Star Shrink plugin for PS (by Russell Croman). I have previously used "Make stars smaller" in Noels Actions for PS. I also did my best protecting the stars while stretching in many small rounds. This is quite a fight with the Veil nebulas that easily get buried in a snow storm of stars. I think I managed better than before and the Star Shrink is a good little plugin as there are some sliders that can be used to better control the shrinking (selecting for different star sizes, strength and sharpness), while Noels Actions is just controlled by the number of times the action script is run, and by finally using the slider on the layer. I have previously also used some of the manual methods (using the selection tool and minimize filter in PS). In any case, I still end up with neighboring stars being connected by a cord of light, giving an odd impression if you zoom into the stars. Maybe it is not a big problem for the overall impression of the image but it is rather annoying.
Any great tips on shrinking stars without odd artifacts? It could be that I am just shrinking them too much and then small neighboring stars that were not completely separated in the data will inevitably show these cords connecting them.
Here is the "big picture" and a crop on the star oddities (ES 5" apo at f/5.9 and Canon 60Da, 21 x 480s, ISO1600):
By the way, I have no moral issues with shrinking stars since they are point objects that are blown out of proportions by our atmosphere, scopes, guiding and chips.