Best 20frames of 87, 1 ms each, stacked with AutoSkakert. QHY183c at 0C cooling, gain 11, offset 50, UV/IR filter, Astro-Tech AT60ED at F/4.8.
This session was also a test for a new SkyWatcher GTi mount with EQMOD software, which worked right out the box, since I’ve been using it with my Atlas EQ-G for years. I didn’t have to reconfigure anything for it to work, which was great.
After the moon, I did some guiding tests and took some 60 second images with only a UV/IR filter, despite the heavy LP at my location. Not too bad, but definitely harder to process out. I tested on the Crescent Nebula and the M22 globular cluster. 11×60 for the Crescent and 30×60 for M22:
Crescent Nebula. 11×60 sec, QHY183c, AT60ED at F/4.8.M22 Globular 30×60 sec, QHY183c, AT60ED at F/4.8.
This combo worked on the GTi mount, but was a little on the heavy side. It works better with just the AT60ED and my 30mm mini-guidescope. The camera is a QHY183C.
The Rosette Nebula on March 15, 2023. 20×180 sec, QHY294C-Pro at -10C, unity gain, offset 60, Optolong L-eNhance filter, Televue TV-85 at F/5.6.
It was the first time using my new camera in heavy LP from the metro area where I have been staying. I went with the L-eNhance filter and picked the Rosette Nebula to test it. The Rosette was just crossing the meridian when I started imaging it. Also, I was troubleshooting the issues I have with flats, which this camera seems to be very sensitive about and worked on that during this session.
I also tried something new for me in processing the image. A relatively new (2017) sharpening procedure called Absolute Point of Focus (APF or APF-R) was done on the image. You can read about it and see two videos on how it is done at this link.
In this case, I had already ran the image through Starnet++ to cleanly remove all the stars. I then used the APF-R method to enhance the nebula only, blending in the stars afterwards. I must say the sharpening seemed superior to most other techniques I’ve used.
Starless version of the image before sharpening.
Anyway, the camera performed well with up to 3 minute exposures. An hour’s worth of data with the L-eNhance filter looked as good as anything I’ve done with the UV/IR filter from a darker site. There was too much LP to go with 5 minute subs, like I used to do with the QHY183c camera and that same filter, however.
As far as the flats, I used my laptop with a blank notepad screen up to illuminate the sensor while having a cheap white-light diffuser taped to the front of my scope. I used 2 second exposures and the resulting flat seemed to work for the most part. Good. I definitely need a way to create flats at night and this method is easy to do with what I already have.
Using all the other data taken that night and adding it together, I came up with the image below. It was the original 20 x 3 minutes, an additional 10 x 3 minutes, 21 x 2 minutes and 8 x 1 minute or a total of 140 minutes or roughly 2.3 hours.
The Rosette Nebula on March 15, 2023. 8×60 sec, 21×120 sec and 30×180 sec, QHY294C-Pro at -10C, unity gain, offset 60, Optolong L-eNhance filter, Televue TV-85 at F/5.6.
It was a Friday night, March 3rd/4th, clear and cool. The Moon was out at 83% full. So, I thought it would be a perfect night to test the Antlia Triband RGB Ultra filter in moonlight conditions to see how bad that would affect it and to get an update on how Comet C/2022 E3 was doing.
Comet C/2022 E3 (ZTF). 32×120 sec, QHY294C-Pro, Unity Gain, Offset 60, Antlia Triband RGB Ultra filter, Televue TV-85 at F/5.6.
Well, the comet’s photogenic appearance has diminished quite a bit since I last imaged it in mid-February. The filter I used probably attenuated the brightness, but by the size in this full field image you can see the comet is much further away from us and receding into the distance fast. Oh, well. It was fun while it lasted.
Next up, I did some EAA-type imaging to test short exposures with the filter on a bright object like M42. It worked pretty good for such a short time (83×15 sec or 20 minutes) of exposure. But, it would need quadruple that time to get right and I was more interested on using longer exposures that would bring out dimmer nebulae better.
So, I switched to the nearby Horse Head Nebula and Flame to test the filter with one minute exposures. I refocused first since M42 looked out of focus and glad I did since it was way off.
The Horse Head and Flame were a better choice for the amount of moonlight out and a better test of the filter’s ability to pick up H-Alpha nebula light. I thought it came out good for only 40 subs:
Horse Head Nebula. 40×60 sec, QHY294C-Pro, Antlia Triband RGB Ultra filter, Televue TV-85 at F/5.6.
When Orion and all the good objects there got out of position and got into the power lines, I moved further east to get more of the Rosette Nebula, which I imaged a few weeks prior. It was also closer to the moon and had a strong gradient due to moonlight and the vignetting my imaging train has. I managed to minimize it in post processing, but it was not exactly easy. After processing, this is the 60 x 60 sec of exposure with the Triband filter I managed to get:
Rosette Nebula with Triband Filter. 60×60 sec, QHY294C-Pro, Televue TV-85 at F/5.6.
I combined that with the data I previously had that was taken with just a clear UV/IR cut filter:
Rosette Nebula, 10×180 sec plus 60×60 sec, QHY294C-Pro, Televue TV-85 at F/5.6.
Not too bad of a mixture. After these runs, I moved to the east and tried imaging a few things there, but the moonlight and LP on that side was more than what the filter could deal with, it seems.
I imaged M101, but the gradient was severe and the image was very difficult to flatten all of that gradient out and preserve the dim areas. By the time I got rid of it all, the colors were drained out and no amount of saturation adjustments were going to bring them back.
So, tried my luck on the M13 Globular Cluster, which was a good test for the Antlia. Still had a strong gradient to deal with, but since it has no nebula parts, it was much easier to get rid of:
M13 Globular Cluster. 75 x 60 sec, QHY294C-Pro, Televue TV-85 at F/5.6.M13 Globular Cluster. 75 x 60 sec, QHY294C-Pro, Televue TV-85 at F/5.6. Full field.
C/2022 E3 (ZTF on Feb 18, 2023, 01:09 to 03:36 UT. 12×300 sec plus 40×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6.C/2022 E3 (ZTF on Feb 18, 2023, 01:09 to 02:30 UT. 40×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6.C/2022 E3 Comet-Only after stacking in IRIS.
Another comet image to add to my collection. This is perhaps the last image from me of C/2022 E3 ZTF for perhaps the next 2 weeks. Weather forecast is nothing but clouds next 10 days or more. By that time, the moon will getting full and the comet is rapidly shrinking in size and fading in brightness. It will still be around, just not as photogenic as it is now.
Also on this night, I tried out a new filter – the Antlia Triband RGB Ultra Filter. Boy, that’s a weird one, let me tell you. Blue as blue can get. lol. But, a stack from SharpCap color balances out in IRIS when setting the blackpoint, so I don’t know? SharpCap refuses to color balance it and leaves it too blue, however. lol So, I just stack and then process first in IRIS for initial color.
This object(s) below was the second or third test subject. Perfect, since this is in strong LP on the north to northwest side. If it can block that, great! And it seems to have blocked it:
M81 and M82 galaxies. 42 x 3 minutes, QHY294C-Pro at -10C, unity gain, offset 60, Televue TV-85 at F/5.6. New filter test: Antlia Triband RGB Ultra Filter.
Yes, it has funky colors, but they’re mostly there, instead of that dull pasty look from duo-band filters. I don’t know? I’ll have to do more testing.
Thor’s Helmet was the first object I used it on. I shot it with a UV/IR then with the Antlia Triband with roughly the same framing. This is just the subs-images using the Antlia. It is about 33 minutes of combined exposure:
Thor’s Helmet. 11 x 180 sec, QHY294C-Pro at -10C, Antlia Triband filter, Televue TV-85 at F/5.6.
Finally, after experimenting with Thor’s Helmet, I went to one of the tougher targets – the Virgo Cluster. Its always either not enough exposure or the wrong colors with duo-band and UHC filters for this cluster. But, does this filter have the blue and enough other colors to give it what it needs? Well, here it is:
Virgo Cluster 29 x 5 minutes, QHY294C-Pro at -10C, Antlia Triband RGB Ultra filter, unity gain, offset 60, Televue TV-85 at F/5.6.
Comet C/2022 E3 (ZTF) on Feb 13, 2023, 02:55 mid-exposure. 68×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6. Portrait version.Comet C/2022 E3 (ZTF) on Feb 13, 2023, 02:55 mid-exposure. 68×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6. Landscape version. North is down.
High clouds and dew plagued my imaging session on this night. My dew heater’s power supply failed right at the start, too.
For this full field image, I took 40 sub-images of the comet between 01:49 and 03:09 UT and another 31 subs between 03:19 and 04:21 UT . I only lost 3 subs to guiding problems, despite the clouds.
I thought all the clouds and dew problems I had would ruin the chances of getting a good final image, but I guess I was wrong. 🙂
Technical: 37×120 sec, QHY294C-Pro at -10C, Gain 1600 (Unity,) Offset 30, UV/IR filter, Televue TV-85 at F/5.6, Atlas EQ-G w/EQMOD. PHD2 Guiding, SharpCap 4.x LiveStacking for acquisition, FitsWorks for dark/flat calibration and debayering, IRIS for stacking and PSCS3 for post-processing.
An earlier, more gaudy version with only 37 sub-images:
Comet C/2022 E3 (ZTF) on Feb 13, 2023, 02:30 mid-exposure. 37×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6. Portrait version.Comet C/2022 E3 (ZTF) on Feb 13, 2023, 02:30 mid-exposure. 37×120 sec, QHY294C-Pro at -10C, Unity gain, Offset 30, UV/IR filter, Televue TV-85 at F/5.6.
C/2022 E3 (ZTF) on Feb 10, 2023, 03:43 UT. 15×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.C/2022 E3 (ZTF) on Feb 10, 2023, 01:30 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.C/2022 E3 (ZTF) on Feb 10, 2023, 01:30 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.
It was a clear Thursday afternoon and early evening, Feb 9th, 2023 (Feb 10th in Universal Time after 6pm here in Cajun Country,) when I tried to image Comet C/2022 E3 (ZTF) again. The clearing didn’t last long, however. Clouds interrupted and got into many of the sub-images. In one case of 30+ sub-images, half had to be eliminated.
But, what I did manage to get was good enough to produce several star-freeze versions and at least one star-streaks version of the comet on this night. Plus, as a bonus one more deep sky object.
C/2022 E3 (ZTF) on Feb 10, 2023, 01:30 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.C/2022 E3 (ZTF) on Feb 10, 2023, 03:37 UT. 31×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.C/2022 E3 (ZTF) on Feb 10, 2023, 01:21 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.
This one was processed as an arcsinh (color) stretch that seems to work for this exposure and didn’t with other stacks. This is the same data as the above image, btw. Different take and look.
C/2022 E3 (ZTF) on Feb 10, 2023, 01:21 UT. 40×120 sec, unity gain, offset 30, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.
I had good luck on the Rosette for a short run from about 11:30 PM till midnight, which is when the moon rose. The data was good and cloud free. Despite the lack of exposure, it was adequate enough to get this level of a display image:
With a very nice comet in the sky, I decided it was time to break down and get the camera I’ve wanted since the advent of the CMOS cooled-camera revolution. It’s the QHY294C-Pro, an 11MP camera with low noise, 14bit output and a larger chip than the QHY183c.
I immediately noticed how much less noise it has than the old CMOS camera and how sensitive it is. I should have got this one in the beginning.
A quick test was done on the Orion Nebula region for 30 minutes of exposure. It came out better than some of my hours long attempts with the old camera or my DSLR. Plus, the nearly full moon was out and produced a very harsh gradient and strong vignetting. The flat I used was for a different orientation of the camera, so it did not fully remove the vignetting, but it got all the dust motes that were on my UV/IR filter and sensor cover. (I should have blew off the dust on both before starting out, I guess. lol)
I cropped the image above down a bit. Here’s another version with different color balance and it is the full field, uncropped original:
First light image – The Orion Nebula and Running Man Nebula. 60×30 sec, Unity Gain (1600,) Offset 60, QHY294C-Pro, UV/IR filter, Televue TV-85 at F/5.6 (480 mm.)
BTW, no dark calibration in the above image. It was a straight raw stack. I covered the scope after the above test and shot darks in prep for what I was really after.
This was my main target, Comet C/2023 E3 ZTF. It was highest in the sky at 8:30 PM local time and I started imaging it right before that. I spent several hours on it, but this image is just the first 1.5 hours of that time.
BTW, my friends at Televue Optics, Inc., liked the above comet image enough to use it on their blog. The post is about comet imagers using Televue equipment for their shots. It is linked here: Televue Optics Blog – Comet C/2022 E3 (ZTF) Imagers
Here’s another version with a less red background color from the moon’s interference:
Comet C/2022 E3 (ZTF) on Feb 4th, 2023, 2:30-4:00 UT. 107 x 60 sec at unity gain, offset 60, QHY294C-Pro, UV/IR filter, Televue TV-85 at F/5.6.
A nearly full moon was out and in the same quadrant of the sky as the comet. Moonlight this bright is tough to deal with and creates some very harsh gradients. Luckily I took some flats the next morning and was able to use them to help minimize that issue.
NGC 4565 Edge-On Galaxy. 222 x 60 sec at unity gain, offset 60, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.M83 Southern Pinwheel Galaxy. 95 x 60 sec at unity gain, offset 60, QHY294C-Pro at -10C, UV/IR filter, Televue TV-85 at F/5.6.
Last but not least, were two galaxies I imaged to test the resolution and sensitivity of the new camera. The image scale lacks for galaxies, but the color and low noise were outstanding.
Remember, all of these were taken on a bright moonlit night a day or so before full moon. I would say the first light test was a major success!
Comet C/2022 E3 ZTF. 16×300 sec @ gain 11, offset 17, QHY183c at -15C, UV/IR Filter, TPO/Askar 40mm F/4.5.
Comet C/2022 E3 was where Earth was passing through the comet’s orbital plane and we got to see a strong anti-tail during the passage.
While waiting on the comet, I imaged a few nebula. None of them serious attempts.
The Witch Head Nebula. 22×300 sec, gain 11, offset 17, QHY183c at -20C, UV/IR filter, TPO/Askar 40mm F/4.5.M78. 8×60 sec at gain 30, offset 17, QHY183c at -20C, TPO/Askar 40mm F/4.5.
Images of Comets, Nebulae, Galaxies and Star Clusters
