A full moon night, but it was clear and relatively transparent. I needed to test some scope adjustments anyway, so I figured I would just do a few of those things, get a shot of the moon and call it a night. I ended staying up all night and shooting a variety of objects, even with a full moon from the metro.
Not only was it a full moon, it joined Jupiter for a conjunction, and I got a shot of that plus a few others:
I had a new astro computer I built from scrap to test this night and also it was a test of the AT60ED and QHY294c with the ultra-mini guider and IMX224 camera on the new SkyWatcher GTi mount. The above equipment was 7.5 lbs, well within the 11 lb limit of the GTi mount and I had great guiding for the most part.
I bagged the four objects above on this night. A Baader UHC-S L-Booster filter was used to block the horrendous LP, which worked pretty well with the QHY294c.
The three versions of the Veil Complex were, for frame 1, essentially the 60 frames stacked and processed normally. Then, that result was put through Starnet++, which removes all the stars and leaves just the nebula, which is frame 2. I boosted that to bring out more nebula and then recombined it with the original to obtain an enhanced version in frame 3.
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:
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.
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.
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.
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:
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:
I combined that with the data I previously had that was taken with just a clear UV/IR cut filter:
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:
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:
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:
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:
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: