ORpilot Loc: Prineville, Or

A photography student of mine lent me the ioptron SkyTracker Pro. He wants me to figure it out and teach a class on multi shot star photography. It has been super rainy out here in Oregon for the past month. So I have not been able to do any test shots. I have watched several U-tube videos on the setup of this tracker. I have done long exposure (20-30sec) shot of stars with good results with my Sony a7iii and Samyang 14mm f2.8. But it looks like I will need software to do stacked photos taken with the tracker. I will need suggestions for free or very low cost software for both Mac and PC. Thanks..

bwana Loc: Bergen, Alberta, Canada

Aligned/stacking: Deep Sky Stacker, Affinity Photo, Photoshop with the Astro-Panel extension, ImagesPlus and a few others.

bwa

Wilderness Images Loc: Apache Junction, AZ.

Look up Sequator. It works good once you figure out how to use it.

Jack

SonnyE Loc: Communist California, USA

I didn't have any luck with stacking until my equipment improved vastly.
A quick Google search turned up this:
https://www.google.com/search?q=Stacking+programs+for+Astrophotography&rlz=1C1CHBF_en&oq=Stacking+programs+for+Astrophotography&aqs=chrome..69i57.31378j0j7&sourceid=chrome&ie=UTF-8

It looks like Deep Sky Stacker leads in free software. Which is where I always want to be. I'm an Internet purist and adhear to the basic idea that the Internet is a free place to share information and ideas.

My last camera acquisition was a Mono camera and the downloadable software has several areas for working with the results. I'm still learning with it, and other programs like NINA (Nighttime Imaging n Astronomy)
https://nighttime-imaging.eu/
But you might like to look at ASIStudio. https://download.astronomy-imaging-camera.com/software/
I don't know if it is priparitory to ASI cameras, but it has some interesting areas for working with Astronomy Images.

NINA is a free program. It is more for advanced work, but is a good place to cut teeth on as students can grow with it. And there is a lot of tutorials on YouTube for it.
Stellarium is a great Planetary program. I began with it, and to this day I use it to find my targets. Most recently I can find an object, and use a link in NINA to designate the target into a sequence for NINA to run.

One thing, most of the Astronomy field seems to be written and circles around PC based algorithm's. Apple based computers can work, but they need to have a Windows platform used in them. That was one thing I considered before getting into this insanity. I wanted to be sure I had the right computer for this stuff.
I spent a month trying to decide IF I wanted to. Then another 5 months deciding on my entry level equipment. In the end, or where I am at this point, two items from the original remain, my telescope (Which is the lens) and my guide scope.
But I got into this because I wanted to see things I could not otherwise do. Long time exposures gather light like a subject gathers color from an airbrush.
My first camera was so poor, I became proficient at longer and longer exposures to get a semblance of an image. And that required I become proficient at my guiding.
I have more bad nights than good.

Tell your students that the Moon is your friend when learning focusing. Focusing was always my bane. But the Moon has some amazing detail to work with.
My trap was seeing the Great Orion Nebula through a spotting scope one winters eve. That was quiet exciting. And I blame Orion for getting me into this.
But do encourage your class to be patient. Forrest Tanaka sez it best:
https://youtu.be/9d0292TBMHo
"I can't think of a more difficult and frustrating, or rewarding, type of Photography."

Good luck with it.

bwana Loc: Bergen, Alberta, Canada

As you might remember, I've often said astrophotography is "10% luck, 20% data gathering and 70% postprocessing". It is probably the only area of photography where you can almost make a silk purse out of a sow's ear!

bwa

Ballard Loc: Grass Valley, California

When I started out, I used DeepSkyStacker for nebulas and galaxies (as mentioned by the other folks on this forum, its free and it works well. It will automatically stack the image photos (also called light frames or subframes) and contains functions for color correction and image stretching to bring out the dim details. It also allows you to use calibration frames which really helps bring out the details and reduce the background noise.

The calibration frames to use in order of importance are:

DarkFrames - Images taken at the same temperature and length as your light frames but with the lens cap on so that no light is taken. You typically will take ~10-20 DarkFrames which are averaged together in the software and then subtracted from each light frame to reduce the thermal noise inherent in all sensors and can vary from pixel to pixel. The thermal noise builds up during the exposure and is temperature dependent.

Flat frames-These frames are used to compensate for non-uniform field illumination (also known as vignetting) which all optics have to some degree. They also will remove dust bunny circles from light diffraction around any dust particles that you didn't get out of the optical train. These frames are taken with a uniform background (e.g. a white tee shirt strapped tightly in front of the lens aimed at the sky). I typically try and get the histogram centered on the exposure. Normally these are not considered temperate sensitive unless they are more than 10 seconds long. The software will take these frame average them together and then modify the light frames normalize the illumination across them.

Bias frames - These frames are used to subtract read noise from the light frames. Like dark frames these are taken with the lens cap on, however they are typically taken with the shortest exposure possible to minimize any thermal noise. Since these are quick I will typically take 50 or more. The software will average these together and subtract read noise from each light frame. (Note: depending on the software used you can calibrate flat frames and dark frames with the bias subtracted out to create Master darks and Flats which are then used with future light frames that you take).

Dark Flats: If the exposure time for your flats is longer than a few seconds then you can add in Dark Flat frames for the calibration of the Flat frames. In this case you want the time and temperature of the flats to match the Dark Flats. (I personally haven't used these as my flats are usually very short).

There are also more advanced programs like pixinsight (which I now use) that has all kinds of routines for noise reduction and other processes. These of course are not free.

Here is a good youtube video that discusses the calibration frames in more detail.
https://www.youtube.com/watch?v=sZmHbxIxZeM

If you get into lunar or planetary imaging then stacking is used again however in this case it is not to add frames to get dimmer objects, but is used to improve the signal to noise ratio of the data due to the atmospheric turbulence.
In this case you typically will take a video and then stack the best images from that video together (known as lucky seeing), typcially 100's or even 1000's of frames. There is freeware for this, including AutoStakkert and RegiStax6. I normally used AutoStakkert for the stacking as it has a 64 bit version so it can take in larger video files and I find is easier to stack with. However I will use RegiStax for processing of the stacked image as has wavelet processing which really brings out the details. There are many videos on youtube for using these routines. If you take more than 60 second videos of Jupiter then winJupos is another freeware routine that can de-rotate the planetary images since the fast rotation rate can start to blur the image after only 60 seconds. (around 120 seconds for Saturn and 240 seconds for Mars).

bwana Loc: Bergen, Alberta, Canada

DeepSkyStacker also does a reasonable job processing comet images yielding a result with both the stars and comet as points rather than one or the other badly trailing. With Comet C/2022 E3 (ZTF) becoming much brighter this might be a consideration.

bwa

ORpilot Loc: Prineville, Or

That's the comet that is supposed to be green and best seen around 2 Feb. ?

ORpilot Loc: Prineville, Or

Thanks, Lots of good info

ORpilot Loc: Prineville, Or

Thanks, I'll check it out

bwana Loc: Bergen, Alberta, Canada

Maybe the brightest around the 1st of February but very visible in binoculars or a telescope now and an easy astro-image if the weather cooperates.

ORpilot Loc: Prineville, Or

hopefully the weather clear someday and I will be able to get some test shot in. Worst case, I'll just do some long exposures like I did with the last comet.

SonnyE Loc: Communist California, USA

Since you mentioned a star tracker, I ran across Sarah Mathews post on YouTube that may be benificial to you and/or your students.
It is specific to Star Trackers, DSLR cameras, and some processing.
50 minutes long.

https://youtu.be/C-X3ky6x8ss

SonnyE Loc: Communist California, USA

I'm betting on June 17th, 2023.
But that's iffy...

ORpilot Loc: Prineville, Or

what's happening June 17 ?