Ballard Loc: Grass Valley, California

I just tried an experiment with stacking planetary images. In this case I took 5 sets of videos of the planet Saturn. Each set consisted of 4 monochrome videos, using a Red, Green, Blue and UV filters respectively. The video rate was between 50 and 100 frames/second depending on the gain and exposure time needed the needed for each filter. Each of these separate videos was 2 minutes long to avoid any rotational blurring of the planet when stacking the individual videos. Each videos was then stacked using AutoStakkert and the best 60% of the frames were used in the stack. To compensate for the rotation of Saturn between the videos the stacked frames for given set of filters were de-rotated using winJupos. The de-rotated images where then combined into an LRGB image (UV was used for the Luminace channel). This was done for all 5 sets of images. The timestamp for each LRGB image was keep and the 5 stacked images where then de-rotated and combined together to form a new image of Saturn. Although the seeing was moderate at best and Saturn never got more than 38 degrees above the horizon this technique produced a decent image of Saturn with more clarity and less noise than the single set of videos. On a really good night I would expect even better results and in the coming years Saturn will slowly be getting higher in the sky for us folks in the Northern hemisphere.
For those interested the images of Saturn were taken with a Meade 16 inch Schmidt Cassegrain telescope with an attached Barlow lens to give an effective focal length of ~8000mm. The camera used was a QHY 290 Monochome camera 2 mega pixel with 2.9 micron pixel size. The video was taken on the night of 10-18-2023 PCT.


All questions comments and suggestions are welcome.

The first image shows Saturn using a single set of images.
The second one shows the image stacking all 5 sets of images.

Saturn from a single set of images

(Download)

Saturn using all 5 sets of images.

(Download)

bwana Loc: Bergen, Alberta, Canada

Both really great images! The 2nd has a bit more detail.

bwa

Ballard Loc: Grass Valley, California

Hi bwa
Thanks for checking out the images of Saturn and for the comment. The stacking of multiple stacks does improve
the image quality. I'll be trying this method more often. I hope to get a night with really good seeing to get some better images.

profbowman Loc: Harrisonburg, VA, USA

I, too, think these are excellent images of Saturn. They are not easy images to obtain.

I do have a question though, if you are only going to work with B-W images, did you need to take cideos with the four filters? --Richard

SkyKing Loc: Thompson Ridge, NY

…I love that you can see the shadow of the planet on the rings…!

Ballard Loc: Grass Valley, California

Hi Richard
Thanks for viewing the photos of Saturn and for the comment. These are actually full color images, the saturation is probably a bit low, however you can see some faint blue in the lower portion of the planet and some browns in the clouds.

Ballard Loc: Grass Valley, California

Hi SkyKing
Thanks for the comment and for viewing the shots of Saturn. Indeed the shadow of the planet on the rings came out prominently. If you closely you can also see the shadow of the rings on the planet.

stepping beyond Loc: usa eastcoast

Those are some really awesome images, color and contrast is paramount.

Ballard Loc: Grass Valley, California

Hi stepping beyond
Thanks for checking out the images of Saturn and for the comment.

profbowman Loc: Harrisonburg, VA, USA

Until you mentioned the shadow, SkyKing, I had not especially noticed it. But it is clear, so I looked up the date of opposition for Saturn and made a sketch showing how the Sun, Earth, and Saturn are arranged. Forgive my being pedantic. Old teachers never die, they just spend more time in outer space! --Richard

(Download)

Ballard Loc: Grass Valley, California

Hi profbowman
Nice analysis. When Saturn is at opposition we cannot see the shadow of the planet on the rings like we can at this time.

profbowman Loc: Harrisonburg, VA, USA

Yes, and at four to two months before opposition again, the shadow should be visible on the other side of Saturn. I think you ought to be proud that you caought the shadow in your photos. --Richard

nervous2 Loc: Provo, Utah

Pretty impressive shots.

Ballard Loc: Grass Valley, California

Hi nervous2
Thanks for checking out the images of Saturn and for the comment.

SonnyE Loc: Communist California, USA

I've been wondering about stacking stacks of stacked pictures.
I see a marked difference between the two images.
I think the multi stacked is clearer, sharper and better defined.
Did you use PixInsight to remove the stars?
Quite impressive seeing how the stacked stacks stacked up.

Ok, my tongue is tied for today.
Love seeing the results your big telescope brings.