Comet C/2022 E3 (ZTF)

It was insanity to try for this. Took most of a week to finally get the shots with speed bumps with a new rig, then to figure out how to process it – there are about 37 ways, most using both acquisition and processing software I don’t have. But I finally found the right instructions for what I do have with one added plugin, which is very good. This stuff is all a huge jigsaw puzzle with no manuals and the software changes under your feet.

The problem is that it is a small, dim target so needs the astrophotography technique of lots of exposures over several hours, which are then integrated into a single lower-noise image for further refinement. But that sort of astrophotography is done by tracking the stars and the comet moves relative to the stars, even in a few seconds. So there is special software to let you align the stars and the comet separately in those sub-exposures and combine them into one image.

Type of Critique Requested

  • Aesthetic: Feedback on the overall visual appeal of the image, including its color, lighting, cropping, and composition.
  • Conceptual: Feedback on the message and story conveyed by the image.
  • Emotional: Feedback on the emotional impact and artistic value of the image.
  • Technical: Feedback on the technical aspects of the image, such as exposure, color, focus and reproduction of colors and details, post-processing, and print quality.

Specific Feedback and Self-Critique

These night sky objects have an emotional impact on me, but maybe not on everyone. They give a hint of the vastness of the universe and of how much we can’t experience in our daily lives. And doing that well takes technology. I guess these objects fall into all the critique categories, in a rather unique way. It takes some background looking at various attempts, but there is definitely a range of good and bad in all of the above categories for the various images we can see online. In all of them, there is good and bad cropping, sharpness, detail, color and all the usual aspects we try to maximize in our daylight photography. Good software helps with all that but like the best cameras, lenses and tripods we all use, at its best it can only give good raw material to work with. And the software, just like the stuff we use for daylight work, is only another tool that has to be used right. There is some leeway with “auto” things, but there’s lots more to it to bring out the best. Just the software processing on this took about 7-8 hours on a fast computer.

This was shot with a 60% moon high in the south, with the comet in the north, so there is some loss of contrast from the moonlight in our moderately light-polluted skies. This is a first quick processing attempt and could be tweaked a bit more after I learn a bit more. Should have a chance to shoot it again in a couple of nights, but the tail may be less prominent and it’s moving away and getting dimmer so it may be a wash.

Technical Details

400mm Askar FRA refractor telescope, ZWO2600MP Pro camera (APS-C sized sensor), Sky-Watcher EQM 35 mount, ASIAIR on-board computer control, Pixinsight processing software.

Trust me – you don’t want to be bothered, but here’s the process:


Hi Diane, I’ve read about this comet but haven’t had the opportunity to see it, live or in a photo. So yours is the first. I can’t comment on the technicals, not even close to being an astrophotographer. But I will say that I love this image. As you said, it shows the vastness of space and makes me feel we are such a minor part in the larger universe. Puts things into perspective, I think.

Anyway, wonderful image and thanks for the background and info.


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Diane - you just gave me something very few humans have seen so clearly. The technicalities and hoops are staggering, but you pulled it off and wow…I am humbled. Both by your talent, vision and persistence to get this and by the universe itself. Just terrific. Thanks for having the fortitude to grasp and yearn for mastery over this tech.

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Amazing photo image, Diane. You did a great job with the comet and the color as well as the composition was well done. I know the camera you have very well, it is amazing how well the CMOS has come over the CCD which I have used a long time. PixInsight is just about as complex as Photoshop and you have that program under control very well. I know what you mean about the night sky. I am just amazed how much is out there and one reason I got into astrophotography so quickly. Well done on this comet.

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Thanks, @David_Bostock, @_Kris and @Dean_Salman! I knew I was standing on a banana peel on the edge of a deep pit when I got into this. I started in the hope of utilizing the camera equipment I had, but quickly realized the new astro cameras are SO much better for this than any “daytime” camera, and that a nice medium-sized refractor telescope will outperform the best camera lenses. So I strapped on my skis and sailed into the pit – much as @Dan_Kearl did a year or two ago. He’s well ahead of me in documenting the universe but I’ll try to catch up.

All this stuff (hardware and software) is very poorly documented and changes under your feet. It’s like a jigsaw puzzle with 1000 pieces and no picture.

Dean, we should all know more about what you do – I think at Kitt Peak.

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Fantastic job @Diane_Miller ! This is really impresssive. You really jumped back in with fantastic gear, and I think it has really paid off in helping you acquire and image this target. And PixInsight too no less!
I tried for three nights to just find the comet with my binocs, and finally found it. I got my DSLR and tracker on it and got a few images last night. Now need to process them (I’m using Deep Sky Stacker and Photoshop).
I would feel very very fortunate if mine turns out anywhere near as good a yours.
PS - I feel the same as you about the night sky. It is beautiful and awe-inspiring especially in Dark Skies. I am humbled every time I think of the vast expanse, wondering what is beyond what we see and know.

Kudos Dianne - going out and getting it!
I let laziness get the better of me
You have shown us that beautiful green glow somewhere in space
Thanks also for the info on stacking