2022-12-04 Mars
10" f/5.6 Newtonian, eyepiece projection using 15mm eyepiece.
Stack of 20% of ~ 5200 video frames (3 minutes).
Video for this image was taken at 8:35 PM EST (12/05/2022, 1:35 UT)
Occultation of Mars by the Moon
I manage to catch a some glimpses of Mars and the Moon through heavy clouds starting moments after Mars emerged from behind the Moon.
I lucked out on 4 counts in getting these images.
First, I was thinking the reappearance was not until about 11:45. Silly me I, when I rechecked early in the evening with Starry Night Pro planetarium software on the exact time for the disappearance, I did not recheck the time of the reappearance! (which was 11:22:00 to 11:23:10) I only went out earlier, about 11:15 to see if I could catch a enough sight of the Moon to get at least a rough focus on the camera so that I wasn't scrambling and wasting too much time later. I managed to catch sight of the Moon dimly through weak points in the clouds. While waiting a good "hole" to verify the focus and identify the right place on the limb of the Moon, I was surprised to see Mars hovering next to the Moon (if you listen to the audio of the first video clip (shorter of the 2) you will hear me saying I thought Mars should still be behind the Moon.
Second, I had managed to get a good focus and didn't have to spend time fine tuning it.
Third, though I would of course loved to get shots or video of Mars emerging from behind the Moon, I did catch it just moments after it had fully emerged. The adjusted time (my camera is currently 17 seconds behind) is 11:24:09.
Forth, but not least, I got enough thin spots in the clouds (no actual openings) to get the shots and video that I did.
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This is an image created by stacking 160 frames (5 sec) from a video clip. Time of video ~11:24:43 PM EST.
North is down.
10" f/5.6 Newtonian, eyepiece projection using 24mm eyepiece.
@pwalker Great captures Paul of the occultation. I guess I am not subscribed as I didn't get alerted. I thought about traveling to see this but I couldn't see that anywhere near was going to be clear. I was entirely socked in.. like a down blanket above me. I could get just the faintest idea of the moon light but only because I knew where it was. Otherwise, nadda. Great for you to capture it. My brother in Michigan was singing the blues as well.. it didn't clear off for him either.
Another Mars image from December 9th/10th using the TEC180. Not my favorite view of the moon, but I did capture enough detail to make out quite a few areas and features. Surprised what a 7" scope can do on a fairly nice night. I was out on the 10th as well, this time with an 11", as I thought we were going to get a second night of good seeing in a row, but it wasn't to be. My stars looked like big snow balls and I was freezing so packed it in fairly early.
I thought I'd throw another Mars image out here. This one from last night but using an 11" Celestron Edge with 2X powermate (no ADC). The system was around 6000 mm and I used the ASI224MC camera at around 2ms exposure time. I captured 20,000 frames and processed 3000 into this image. Finally seeing some decent results from this scope. What I'm realizing is that large aperture scopes, or maybe scopes with obstructions, need better seeing than refractors for pleasing views. The scope was able to easily break the trapezium into 6 stars with hints or more. The Hadley rille was easily viewable.
No doubt your equipment is better than mine but expect your seeing at times is better than mine as well. The first of the 2 latest images and the one in the post previous to that are way sharper than what I have been able to get. The thin "finger" on the left side extending north (up) from Mare Cimmerium is detectable in some of my images but is very smeared out. You can take a lot more frames with the ASI224MC camera than I can take with my digital camera, but we are both stacking about the same percent of frames (I have been using 20%), so it seems the quality of all your frames are probably better. You may be using different software to sharpen it as well. Do you use PixelInsight with planetary images? I use AstroStakkert!3 for stacking and wavelets in Registax 6 or sometimes unsharp masking in Picture Window Pro 7 (I don't know anyone else who uses Picture Window) for sharpening sometimes one works better than the other. I've been using AstroStakkert for about a month now.
It would be interesting to see what the stacked but unsharpened image looks like. Either posted here or sent directly to me (in jpg format please).
@pwalker Hi Paul, there could be some equipment differentiation but I don’t think it’s going to be significant and I don’t believe software has much to do with it either. You’re using big dob’s of good quality and those are probably about as good as my 11” SCT. My 7” refractor is good for a 7” scope, but not better than my 11” SCT for planetary in good seeing. I do think that the refactors give a better view/experience in less than great seeing which may be a lot of the time here. I can tell you that I’ve been very frustrated with my abilities on planetary imaging for some time and the very biggest factor seems to be catching the good seeing. Having spent a lot more time doing it, my seeing changes based on the azimuth of my scope at my locations as I think, but don’t know for sure, that seeing is affected by ground topography in certain directions. I was focusing on maximum altitude but this wasn’t my best seeing position. It’s not intuitive and I’ve only learned this based on taking lots and lots of video. I have about 5TB of video. Here are some other things that may help get a bit more detail. I will cover this in my presentation but some of this below.
1) Capture lots of video. To be lucky you need to capture lots of video.
2) Exposure only about 60% max. I don’t know how this relates to your camera. I used to shoot at like 90% which caused issues with finer details as I had many over exposed areas.
3) Shorter exposure times when seeing is worse. My latest Mars images were 2ms, Jupiter 3-5ms. Using lower gain targets helps to get to faster exposure times.
4) Adjust your overall system to capture at an F ratio of 5 x pixel size (in microns). This will optimize your captured image scale. Use barlows to adjust your system focal length to this. You can go higher in excellent seeing but likely at the expense of more noise/worse SNR.
Autostakkert and Registax are great tools, but there is another tool which will do all of that functionality together, easier and faster. Astrosurface, which is free. I wrote about it in one of my posts and have turned my brother on to it as well. At a minimum, I use it for processing after using autostakkert for stacking. Registax is old code, and much of its functionality is klunky and Astrosurface does the ‘back end’ really well. Whenever I thought Registax was doing something special, I found I could do the same with Astrosurface easier and faster.
I’ve done a bit of testing and comparing, and don’t believe that you’ll get differences on average between the tools, but I think you’ll find Astrosurface easier and quicker to use.
The capture ratio or exposure % or max isn’t something I’ve invented, you can find this on cloudy nights planetary imaging forums. I’ve done a fair bit of reading as well as getting feedback from my brother. He’s the one who told me 5ms was too long an exposure time in bad seeing.. I didn’t do a direct comparison that night, but I want to before I do my talk.
My brother, with his Orion dob, has taken fantastic images and I believe it’s mostly because he has had some superior days of seeing. A 14” aperture doesn’t hurt either which is 50% bigger in area than an 11” scope! I processed his data while I was in Michigan and it was some of the best data I had ever seen (better than I’ve ever gotten). Our seeing is really terrible most of the time. Deep sky can tolerate it, but at the expense of bloated stars which we can of course fix in post processing.
Just some thoughts here.. good luck.
Terri
p.s. you asked for an unedited but stacked image. Here you go.
