Six images bagged in one night, although a few need at least another nights worth of additional time. Big city light pollution was circumvented with an Optolong L-eNhance filter.
30 second sub-images for the DSO’s. The moon was 5 frames stacked in SharpCap 3.2. The Cone Nebula has 130 subs from last night and 63 from a previous session. I also shot M51, but it was only a few frames before twilight and was not really enough for a display image.
An early morning imaging session. I setup after 1:00 am and imaged until sunrise on Tuesday, Dec 3, 2019. I managed to get decent amounts of data on the Horse Head and Owl nebulae, but I only got a little bit of the Cone before it went behind trees.
I will definitely want to shoot the Cone again with 2 more sets of data – one with the Optolong L-eNhance filter and one with a UHC filter. It is a beautiful area with broadband filters, but too much LP from my current site to do it justice with one of those. I think the two filters together shooting separate sets might do it justice from this place, though.
Sunday evening was beautiful here in Cajun Country and I did not let the night go to waste. I shot a number of things, but I went back to the Cave Nebula early on to add more data to my existing image of it.
I shot the moon next, even though the seeing was not that great. I shot 10 stills starting out slightly underexposed and progressing to over-exposed to show the dark part that was lit by Earthshine. My experiment to blend them all together was not what I had in mind in terms of look and feel. Plus, I had shot them in 8-bit mode instead of 16-bit mode in SharpCap 3.2. It was a learning experience, I guess. I’ll figure it out one day, hopefully.
I did the Monkey Head Nebula last and it hardly needed any post-processing. 50 minutes worth of data was enough to show most of it. Guiding and composition were good and the image was easy to post process. I packed it in after this, since it was nearly 2:00 am and I needed at least a few hours of sleep before work Monday morning. lol
Like before, these images were all taken from a metro area with Bortle 8 red zone light pollution levels. An Optolong L-eNhance filter was used to shoot through the muck.
This is data from the same dates as images in the three previous posts before this one. There were so many things I wanted to shoot in these sessions that were Ha, but needed 3 or 4 times more exposure to do them justice. I scouted for what would be brighter Ha targets and did some test stacks trying to get the feel of how much certain things would need.
This one was one of the bigger and brighter targets I tested, but I could tell the less than an hour’s worth of data would need lots of work to make it into a presentable image. Another one of those works in progress, I guess. I gave it nearly an hour but it really needed at least double that as a start and 4x that for something exceptional.
A mixture of 120×30 sec exposures taken with a L-eNhance filter and a mixture of 15, 30 and 1 minute exposures taken with a UHC filter. About an hour and 30 minutes total. The 120×30 set was at 30 gain and -20C.
I am starting to like the 30 gain setting, since it gives the best results with shorter exposures. Over 40 is too much noise and under 30 it is just too slow.
When the set began there was no matching dark to subtract, so I was using one at gain 20. I stopped after about 10 shots and took some darks and then restarted shooting. I’m glad I did since the amp glow was starting to show up bad on the right side of the frame. The new darks overcame it and the glow averaged out after a while of LiveStacking with ShapCap 3.2.
What luck! First light for new filter is the day I received it! Thanks to the clouds for staying away. What I wanted to test was my new Optolong L-eNhance dual-band nebula filter, which is similar to the UHC filter I already own but with a narrower bandwidth and a more even color rendition across the frame than the cheap UHC one I’ve been using. I got to try it out before the run of good weather we’ve been having ended.
I was a able to test it on the Veil, which I recently imaged, and the Cave Nebula, which I had never shot before. I am very pleased with the results. Even color and illumination and better rejection of LP.
The Veil nebula was shot like I’ve been doing – 30 sec sub images at high gain. The Cave was long exposures of 4 minutes and I managed to get 26 subs. The Veil is a finished image and the Cave Nebula is still a work in progress. It seems the long exposure, 4 minute darks I used were not too good of a match and there are numerous hot pixel trails left to manually repair or clone out still left to do.
I also tried it on two reflection nebulae, one being the Running Man in the image below, and it was not as good as my UHC filter. I also tried one star cluster, M35, and it is the last image below. No galaxies yet, so I’m not sure how well it will work for those. Maybe next time I will have to try for one and find out.
I am amazed at how much signal is in just 6 minutes of sub-images for this new camera, QHYCCD’s QHY183c. When you take the shot, there is really not much there without significant stretching of the image. But, since the noise is so low with this cam, it can be boosted beyond anything a DSLR image could keep up with.
Now, I did do quite a bit of noise reduction on the Veil image included here, but it had enough signal to preserve enough detail to make the image adequate for a display image. I reduced it 50% to smooth it out more, but the original size is OK, too, just quite large to be downloading on a mobile phone.
Clouds were why the session was so short. I was clouded out when it was in a prime position early on, then it went completely overcast at the end. In between, I manged to get the 6 x 1 minute subs . I gave up and tore down and stowed the rig after I couldn’t shoot anymore. Almost as soon as I had put away the last piece of gear, I went back out and it was totally clear, just like when I had started setting up. Sucker holes and I fall for them all the time. lol
I was actually just testing some tweaks to my laptop I did hoping that they would improve performance. I added memory and updated a few drivers. Stability was vastly improved, but the speed of the machine lacked. I could not do a, “live,” shot of the moon at the lower exposure needed. It would not stream with the exposure less than 350ms. Too many frames per second for it to keep up with, I guess. Means I need another field laptop. 🙁
I started this session at midnight on Sat/Sun, Nov 2nd/3rd, 2019. It was cloudy, but the forecast said it would eventually clear. I went to bed early and woke up at midnight and checked and sure enough, it was clear. I managed to get these two objects plus some other stuff that I haven’t had time to mess with.
The seeing was horrible when I shot the Crab and it shows. I decided to take that data and combine it with previous efforts to see how it would look. The image below is the result of 3 different sessions, 3 different cameras and 2 telescopes. Check it out:
I bought the adapters needed to mate my new QHY183c camera to my Canon lenses. I tried it out with the 200mm F/2.8 telephoto. No way to control the F-stop diaphragm, since it needs a Canon camera to do that, so I had to shoot with it wide open. BTW, this was from the light polluted metro area I’ve been shooting from lately.
Since this is one of the cheaper lines of Canon lenses, it suffers from optical imperfections like astigmatism. That makes the red focus to a line up and down and blue and green focus to a line left to right. It really messes up the star shapes and there is no way to fix it except to stop the lens down to F/3.5 or higher. Oh, well…
I’ve been trying to get enough data in one session for a rendition of the Horse Head with my new camera. Each time, my session was cut short due to trees in the way, the break of dawn or clouds. This morning was no exception and clouds ruined my session even before the sun could.
No matter. I took all the short, incomplete sessions I had and combined the data into one composite image. I even used the BW stuff I had before I got the camera working correctly with the right drivers. I estimate I have about 70 minutes of time in the above image, with up to 4 separate stacks combined into it.