Here’s the very first stacked image taken with my new Astro-Tech AT60EDP. It’s a 60mm, F/5 Petzal telescope with 300mm focal length. This was 64×180 sec using the new scope. Location was a Bortle 8-9 zone with a bright moon out, 48F, clear and above average transparency.
Comet 62P/Tsuchinschan near the galaxies NGC 4608, NGC 4596. Also included are M58, M59, M60 and other faint galaxy fuzzies in the Virgo Galaxy Cluster.
M4 Globular Cluster, Antares and friends in Scorpio. It was still 1st light night for my new AT60EDP, but 5 am instead of 6:30 pm. ,This is 10 x 3 minutes with a QHY294C, Antlia Triband RGB Ultra filter from a Bortle 8-9 zone. I
It was a clear Sunday evening on Jan 28th, 2024 and I had to do some tweaking to the scope, so I took advantage of the good weather and did some imaging to test the results.
After the tweaks and adjustments for the scope, I went straight to Comet 144P/Kushida, which was well placed in the early evening sky. I took 45 minutes worth of subs and above are the two images I generated from this data.
I shot of few sub-images of M35 the last time I was out and wanted to return to it now that I tweaked the scope. I got two hours of data on it and it came out reasonably well.
By the time I finished M35, the moon had risen high enough to drown out any dim nebulae and whatnot, so I shot the moon itself. It was still rather low in the sky, but did not come out too bad:
I resized it 200% for this display image and did some sharpening with the AstraImage Maximum Entropy Deconvolution filter in PS. Yes, not too bad at all for a 60mm scope.
On this night, I was mainly going to try making adjustments to the new tilt plate gizmo for the AT60ED and see if I could get further improvements to its field. Even though it was clear at first, the forecast was clouds coming in for a few hours, so I was not looking to take any keeper images and I wanted to get this testing done instead.
I had just completed star aligning and noticed a comet near Aldebaran in Taurus on the charts, which I had just used to sync the scope’s alignment with. It wasn’t listed by SkyHound’s Comet Chasing website, so I took a few images to see what it looked like and how bright it was. Only 15 minutes of exposure, so it’s not much, but it is what started the night.
I was really after the Comet 62P in Leo, and this runt comet was interesting, but I wanted to do more testing of the tilt plate thingy. I was going to come back to it, but clouds invaded and stayed until 11:00 PM or so. By that time, I still had about 2 hours for the comet in Leo to get to a good spot, so I took images of M81 and M82 to kill time.
I lost/missed focus for this dataset and the guiding for it was terrible. Plus, it wasn’t quite as clear as it needed to be from lingering clouds and moisture. I salvaged what I could. I only include it here to remind me to focus before each object if I want a keeper image and remind me it takes 3 SharpCap polar alignments and not just 2 to get good tracking.
Finally, 62P Tsuchinshan is high enough to image, so I star taking images of it. I realized the first few subs were not in focus, so I stopped and redid it. But otherwise, I was able to let it take pictures on its own while I caught a few winks. All in all, 68 images of it were taken or 3.4 hours worth:
Transparency was only average to slightly above at times for this night, so it wasn’t as clear as predictions. But, I did notice what the focus was doing and I now have a better handle on it. Plus, now that I know about it, I might have to try for more sub-images on that first comet and see what shakes out.
In the second week of 2024, the weather gave me a break on a Tuesday evening. It was going to be one really clear and totally transparent night and I could not let it pass without imaging something.
I was setup and was taking flats by dusk. But, the object I really wanted to get data on was not going to be in position until about 2:00 AM the following morning. So, I needed to kill time and this area of the sky in the image above (Auriga) was in prime position. I managed to get 3.75 hours before the mount reached the meridian and it was time to flip it.
At this point, I had another 2 hours of waiting, so instead of flipping the mount, I went with imaging the Virgo Cluster with this very wide field rig. Not too bad for only two hours, but it needs about double what I had time for.
Finally, Leo and Comet 62/P, the object I was really after, was high enough to get data on, and I managed 45 sub-images of it. I have two versions. One is the cropped version above that I did first.
The full field version is below, which I restacked a couple of times to get a better background-stars-only image. One stack was done with SharpCap, and then I re-calibrated the subs in FitsWorks and stacked them again in IRIS, which was not as noisy as the Sharpcap stack. These two stacks were combined and then the comet-only images was composited in.
Not a very big comet, but it has a tail, at least. I don’t think it will get much better than this, unfortunately. It already passed perihelion in December and will make the closest approach to Earth before month’s end. It was forecast to slowly dim over the next few weeks.
I stopped imaging the comet shortly before dawn. I had to work that day, so I grabbed my scope and laptop and brought them in and tried to sleep for an hour or so. I had napped during the night, but still lacked enough sleep to function. It took a couple of days to recover enough to do the processing for these. lol
It is a Wednesday in the middle of the week, but the weather is clear and earlier that day I just received my new ZWO tilt-plate adapter. The goal of getting it being to fix my skewed field of view of the AT60ED with the QHY294C camera.
I stuck it on, hooked it to the scope and twisted just one screw up and down a couple of times to see what it would do, then just barely turned it, just a bit and locked it down with the screw beside it. This screw was in line with the landscape orientation of my camera and also the way the field seemed to be tilted.
I crossed my fingers and started shooting 3 minute exposures. It had looked good with 2 sec shots, but I was not convinced until I saw the first normal sub-image.
Amazingly, the field was almost perfectly flat with just a little elongation in one corner! It’s possible the extension tube I removed to put the adapter in place had sagging issues, but I think I just got lucky with the adjustment. Maybe both. lol 🙂
I wasn’t planning on staying out long, since this was supposed to be just a test of the adapter session. I thought I would be adjusting it all evening and not trying to shoot keeper images.
I picked the M78 area, since I had some data from the last session that got cut short by clouds. It needed more time and this was going to be it.
I bagged 47 sub-images and with the 36 from the last session added to it in PS, the image above is the result. The bad parts from the previous session with the worst star elongation were replaced with the new, which was mainly the top left corner.
Finally! Success! I was about to spend more money on a Petzval scope. Glad I waited and tried this first.
It was the last two nights of the year and I had clear weather. What luck!
So, on Friday night, Dec 30th, I had to take care of unfinished business with the Horse Head from the last session. I had something to block the parking lot lights from next door this time. While waiting for the Horse Head to get into position, I took images of M33 (above,) which I hadn’t tried with the AT60ED, yet. It came out decent, I guess.
While taking the Horse Head, I noticed on the charts that a comet was in the field. It was C/2017 K2 (PANSTARRS), at magnitude 11.9 according to Cartes du Ciel.
I imaged until almost midnight on Friday. I left the mount setup and brought in the rest with plans to try again on Saturday, New Year’s Eve.
On New Year’s Eve, my plans were to go for M78. While it was getting high enough, I got some more data on the Heart Nebula – an hour and six minutes. I mixed it with the salvaged Heart job from a couple of months back at about 22 percent to help fill in some noise.
When I got going on M78, it gave me problems with tracking. I finally realized it was my guide calibration and after redoing it, I was back in business, but wasted almost an hour figuring that out. Consequently, by the time the clouds came at about 10:20 PM, I still had less than 2 hours of data. Oh, well… I’ll try again next year! lol
On Wednesday afternoon, Dec 20th, 2023, it was clearer than predicted. So, I broke out the scope and setup to catch the first quarter moon and test a filter I purchased last year that I only used twice.
My main problem with using this filter was getting my flats to work when using the QHY294C camera. I was never really successful last year and I had to manually do flat calibration in FitsWorks, which was a pain. So, my first step was to get a good flat and hope that it worked with the 3 minute exposures I planned to use.
Conditions that evening were predicted to be clear, but only average transparency. In actuality, it was average to below average with a few high clouds that came in periodically. Oh, well… I was not expecting to get any keepers this night, but I still wanted to test that filter.
The Antlia Triband RGB Ultra filter, a lower cost triband filter that I had mixed results with at a dark location last year, was what I wanted to use and test from my heavily light polluted metro area location. It would be the first time to try it in this kind of heavy LP.
So, the first image at the beginning of the post is how the UHC-S filter performed with 9×3 minute subs. The conditions were better when this image was taken, so keep that in mind.
Next, here’s how the Antlia Triband RGB Ultra filter did with roughly the same exposure on a below average night:
Almost a match for how much nebulosity it picked up, but the key differences are the star halos that the UHC-S filter tends to produce on bright stars and the lack of halos for the Antlia filter, plus the much stronger blue channel with the Triband.
Next, I put it to a real-world test with 50 sub-images of the California Nebula:
I noticed during the acquisition of these that the filter was performing really well, and my flat was working reasonably well. It was not perfect, but good enough for what I intended to accomplish.
I have a second version of the processing using a PS Starless action. Not as clean as a removal as StarNet++, but it’s very fast!
After this, I wanted to try it on the Horse Head and Orion Nebula. I started on the Horse Head, but didn’t get too far because my scope was starting to point directly at the parking lot lighting next door. Once the light was directly hitting the lens, that was it. So, only 4 sub-images were good out of the dozen or so I took.
I opened the stack in FitsWorks while still imaging it and cropped out the bad part that had caught the direct view of the streetlight. I spent only about 5 to 10 minutes fussing with it in FitsWorks, which has very limited image editing tools. It came out much better than I anticipated:
Here’s the same image, but it is the uncropped, full-field. I worked on it in PSCS3 to repair the damage from the streetlight’s strong gradient in the top left corner and do a better processing job than what FitsWorks does:
So, my conclusions are this filter, with a good flat, tends to work better in heavy LP than the UHC-S filter. Mainly because it doesn’t produce bad halos around bright stars. But, it is also because it has a great blue channel, unlike the UHC-S. That sure makes color balancing easier and I can go after broadband targets in addition to just nebulae.
BTW, I never did get a shot of the moon that night. The filter test results were too good and I didn’t want to waste any time that I could otherwise use to test it on more nebulae.
It was a very clear night after a cold front had passed and enough time had gone by for the winds to calm down again. I setup before sunset and got ready.
The Moon was out and in conjunction with Saturn, which was right above it. Unfortunately, the field of view was too narrow to include both in one frame without rotating the camera to another angle. So, I just shot the moon
I composited together an overexposed shot and the first image and blended it to show the moon among a few stars. Not quite what I was hoping for, but you get the idea.
The Pleiades is one of those images I end up with when I want to kill time while waiting for what I really want to image. In this case, it was the Seagull Nebula, which was my main target for this session.
I maxed out for one night with 4.5 hours on this object, which when added with the session from last week, gave me nearly 6 hours on the Seagull. Finally, an amount of time that gives very smooth results – once you add them all together properly.
The only serious image out the bunch was the Soul Nebula. It was the only one I planned for and was my main target. I managed to get 3.8 hours on it, with .8 hr on one side of the peer and the other 3 hrs on the other. BTW, all images were taken with a QHY294c, a UHC-S filter and a AT60ED on a SkyWatcher GTi goto mount in Bortle 7-8 skies.
The rest of the images were mostly done with 30 sec exposures at high gain (i.e., 3000. I normally keep it at 1600.) Like I said, I was sightseeing and doing an EAA experiment.
The Elephant’s Trunk Nebula area was the longest of the 30-sec shots, 240 x 30 seconds. I still had to combine it with about 30% blend of a 90 minute exposure taken with another camera, but the same scope. It was still too noisy even after 240 subs.
So, the 30 sec high gain experiment for EAA type imaging is not up to par with what I could do with the QHY183c camera. It did well on open clusters, at least. Oh, well. Live and learn, as they say.
It was the first clear night since the last session on Nov 3rd. I wanted to see this comet and try to get images of the Heart Nebula. The comet was first in line since it was already getting low in the west after sundown. I forgot to adjust the gain down and shot it at the highest gain setting I usually use when focusing and star aligning. Surprisingly, I was able to salvage the sub-images and get a usable image from them. BTW, the comet seems to have a tail, but it could be an artifact of the gain setting or something.
Next up, I did a quick look see at M42 and the M46/M47 Open clusters area. I wasn’t planning on keeping these, but the data on my main target of the night, the Heart Nebula, was horrible. So, I thought better of just ditching these sub-images.
I also did a short run on the Cone Nebula/Christmas Tree Cluster area of 10 x 3 minutes, plus I got a few frames of M78 and M44. The Cone area is not too bad considering it is only 30 minutes of time. M44 was a very quick look and I just wanted to see how it would fit with this rig I was using. But, M78 needs a couple of hours to even begin to look nice and I only got 21 minutes worth. Oh, well… next time.
And, finally, here is the salvage job on the Heart Nebula, of which I had two sets of data. One was slightly out of focus, the other had a terrible gradient from an IR source that was pointed right at the lens and I think some of it got through the UHC-S filter, or it was a reflection off the front glass.
What I ended up doing is taking the slightly out of focus stars and removing them totally, then taking the good stars from the data that had the bad gradient and combining them. Still noisy and not that great, but reducing it to 33% smoothed it out enough to pass as a display image.
Oh, well. Another reshoot for this one is in order and also for its close neighbor, the Soul Nebula.
Images of Comets, Nebulae, Galaxies and Star Clusters