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.
Here is an interesting experiment I did in shooting short, 10-sub x 30 sec “subs-stacks” with LiveStacking in SmartCap 3.2 and stacking the stub-stacks in IRIS. I used Fitsworks first to orient the 5 min stacks taken after the meridian flip with the first batch. Final post-processing was done in PS.
I squeezed in two other shots this night – one of the moon and a test for guiding I did on Mirach. The test involved changing the PHD2 camera selection to the Ascom Toupcam driver instead of the regular version I used that gave trouble in the last session. That solved a problem with the camera dropping and losing connection.
Similar to NGC 981 above, I did twelve 10-sub stacks of Mirach for 5 minutes each for a grand total of 60 minutes of exposure:
The moon was out and after shooting NGC 891, I captured it in a .SER movie with 100 frames. I used 20 to make a still with the AutoStakkert software. Here’s the result:
Very clear conditions this night, but seeing was mediocre, with strong LP and moonlight interference. Cold for Cajun country, too… it got down to mid-to-upper 30’s. Brrr…
I was testing a used i7 laptop for use with SharpCap 3.2 under a bright moon on Saturday night, Nov 9, 2019 and the session yielded two images so far from the data. I was also testing a different guide camera. I switched from the Orion StarShoot mono cam to my Rising Tech IMX224 color eyepiece cam.
I had mixed results in testing. It was promising at first, but after several hours, some instabilities with SharpCap and the guider cam means I still have work to do to debug some possible driver and compatibility issues. Oh, well. At least the new laptop seems to be able to stream the camera data better than the old Panasonic ToughBook I was using.
As far as the two images, the top one was the first object I imaged since I used it to do alignment and focusing . I really wanted to see the “ghost” since I missed out getting it on Halloween. It is a crop centered around the star and galaxy at 100% resolution.
The second one was in the muck and between the bright moonlight, the LP and the terrible seeing, I thought it would be hopeless, but I managed to pull out some data that at least shows some of the spiral structure of M81. It is the full field of the camera. The linked image is at 50% reduction from the full size, 20MP final image.
Pretty clear night but the seeing sucked bad. The moon, which I did not shoot this night, was at 89%. Normally, I would not shoot on a night like this, but I had some testing to do, which was a good enough reason to get 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. 🙁
Images of Comets, Nebulae, Galaxies and Star Clusters