M42 Stacker-Lite Experiment

[Hankmeister3]

I'm learning a few more things about DSS and my ArcSoft PhotoStudio 6.0. I'm still playing around with the sequencing of the various post production features PhotoStudio offers from layering, to tonal adjustments, to color balance, despeckling and Gaussian blur. There's a lot more features I can list but I've probably touched on them in past topic posts.

I've added a few more frames to my last attempt (5 lights/frames) and am still performing a "Stacker-Lite" process on M42 without using darks, flats or bias frames. This image is the result of a stack of 11 "lights"/frames and 7 layers of image tweaking in PhotoStudio 6.0 though I think DS Stacker dropped one of the lights. The exposures ranged from 6 seconds to 145 seconds at f/4 with a total of 10 minutes of "data". Also, no filters.

I generated three different images from the original DSS stack and this one was the best overall though a second image actually did resolve the Triangulum but various color interfaces were a bit goofy probably because I "over-processed" that particular image trying to resolve Triangulum.

I like targeting M42 because of the dynamic range challenges it presents as well as trying to resolve Triangulum in that super-hot core of M42. I think I'm to the point where 6 to 10 stacked lights with no darks, flats, or bias frames may be enough to overcome 90% of the dynamic range problems of most DSOs. However, I'm definitely seeing where hours and hours of data are needed to overcome borderline sky conditions and to capture much greater details of DSOs as well as planetary, lunar and solar features … not that there was ever any question in my mind that more is indeed better in AP. The minimalist approach clearly has imaging limitations but the final image of such a short-stack can be two to three times better than the image produced by a single-frame because of the extra data.

An Orion 6-inch f/4 fast Newtonian astrograph originally captured the donor images vis a vis an unmodified Canon EOS 77D.

[Juno16]

Great looking short stack Henry!

Very clean image with nice coloration and good details. The trapezium looks great!

Thanks,
Jim

[Hankmeister3]

Thanks, Jim. I greatly value your enthusiasm and encouragements.

Trapezium is still a blob but at least the outer limits of that little cluster is defined. It's the best I've been able to do with Trapezium. I think under the proper skies and with really good, nicely spaced captures from 5 seconds to 180 seconds, I might can come up with six "lights" that would actually show a resolved Trapezium with nice nebulosity. Certain 10 lights would do the trick. If I remember correctly these 11 frames were captured under Bortle 3 to 4 and Pickering 5 skies, nice but not great. I'll need some very steady seeing and exceptional seeing conditions to keep star bloat to a minimum, too.

Hopefully on our vacation to the southwest starting next Wednesday, I'll be able to image 3 out of 10 nights. I hope to get some healthy strings of M42, M45, Rosette Nebula, the Horsehead/Flame Nebulas, maybe some galactic DSOs in Leo and maybe five or six other iconic DSOs. Can't wait to get our of the Midwest ice box.

I'm still entertained by the Stacker-Lite process though I still think I'm reinventing the wheel to one degree or another.

[Thefatkitty]

Henry that's great, wow; I'm impressed!

Enjoy your vacation and hope you have clear skies!

All the best,

[Hankmeister3]

Thanks, Mark. This morning my wife and I checked the weather down Tucson, AZ way and it looks like this coming weekend may provide some opportunities for several sky safaris. But forecasts change so we'll be monitoring night sky conditions on our way out to the southwest. Hopefully I'll be able to get another session or two in on the rest of our trip into upper Arizona and southern Colorado.

[STEVE333]

Very nice result Henry. Nice colors and nebulosity.

Steve

[Hankmeister3]

Thanks, Steve. I have a ways to go refining the technique (if there really is a technique to my Stacker-Lite brainstorm) but I'm generally pleased with the above result. I culled out a few frames today and restacked 8 images instead of 11 and got some really nice round stars (two of the frames/lights I eliminated were a bit off on the tracking) but I noticed some details in the middle of the nebula essentially went missing. Yeah, nine or ten minutes of "data" isn't a whole lot to work with but I'm still making a commitment to getting respectable results from an 8 to 10 frame/lights stack without darks, flats and bias frames.

I did learn a few more things about my ArcSoft PhotoStudion software features but I found only one of the four 8 stack images I generated today came close to the image on this post. As we all noted before, using 6, 8 or 10 frame stacks will only result in a two to three fold improvement in the overall post-production image. Plus, I need better captures to work with taken under very nice, dark skies with steady air since committing to such a low number of data frames requires everything in the production chain to be the best that best can be. That being said, I see where capturing gobs of data frames and adding them to a pre-existing data base is the most efficient way (despite the hours involved) of guaranteeing a quality final image.

[Hankmeister3]

Here's my second attempt on this 11 frame/light stack. I'm not sure if this is significantly better but I believe I was able to define the Trapezium "blob" a bit more and add a bit of luminance/gain to the overall image. I tweaked the color balance a bit, too. I may have gone a bit too much on the magenta but I like it. Rather magenta than green … heh!

[Hankmeister3]

Now this M42 image is interesting, The 5 frames/lights which make up this stack were also captured with my Orion 6-inch f/4 and an unmodified Canon EOS 77D. I think it gives a slightly different look at the Orion and Running Man Nebulas (other than a difference in orientation, that is) and a better defined Triangulum though its stars still aren't resolved. And this image (after 4 tries!) stacks only half of the lights that I used to generate the previous two images above. I'm sorta scratching my head on this one since we're dealing with half the data but this might be validating my thoughts regarding the necessity of having quality donor images when stacking such "minimalist" stacks. It also could be, in such a small stack, exposure bracketing could be a fairly significant factor in the out come of the final stack. More experimentation is certainly needed to determine what the optimal exposure bracketing would be in stacks smaller than 10 lights.

More than likely what makes this image more appealing to me are the different post-production tweaks and sequences of tweaks and layers of this specific stack which yielded what I think is a more pleasing image of M42 - at least to these two old eyeballs.