The last time I checked, Astrobin had nearly 400 pages with over 20,000 images of M42.  It's an object that is visible to the naked eye, it's large, and it has gobs of detail and color, which is why it's among the most popular targets in the sky.  It seems that as soon as anyone gets a new telescope or a new camera, M42 is often the very first object that get's imaged.  That means that a lot of those 20,000 images are simply first attempts and frankly, not very good.

My First Atempt
My own first, not very very good, attempt at it was back in (maybe) 1969 on a very cold winter night outside of Detroit using my homemade 8" F/6.7 Newtonian with an Argus C3 camera loaded with Tri-X 400 film.  I can still remember the crunchy snow and how cold my feet were while tried to keep my breath from fogging up the eyepiece as I hand guided for maybe around 3 or 4 minute exposures.  I might have only spent $150 dollars building that scope and I couldn't afford a clock drive so I had to guide by hand.  I didn't know how to focus very well and the entire mechanical setup to hold the camera was a complete kludge but I was determined to see what I could get.  I processed the film in my own dark room in the basement of my parents house and out of maybe seven tries, only two images were guided well enough to print.  So I stacked them in my little enlarger and here's the result.  If you compare this first image to my new image here, you'll see that it really only captured the inner, bright core of the nebula.



Regardless, at the time, I was VERY proud of this photo and I actually still have that 55 year-old print framed and sitting on my mantle.  It mostly serves as a reminder of how long I've actually been at this and of how I wound up getting into the field of optics in the first place.

My Second Attempt
Fast forward to 2015 when I used my first newly acquired Edge 14 with a HyperStar adapter and a modified Canon DSLR to go after M42 a second time.  The HyperStar adapter produced all manner of strays that I had to fix by hand to get the image into a good enough state so that I could post it.  You can see that image here:  https://www.astrobin.com/153639/C/?nc=&nce=.  Again, at the time--about 9 years ago, I was pretty pleased with the result.  

As I moved my long focal length telescopes to remote locations, I eventually lost the ability to image a wide enough field to make it worth imaging M42 again.  That lasted up until I installed my GTX130 refractor in Chile, but by then, I didn't have much interest in re-imaging M42 again.  Still, my satisfaction with that old HyperStar image had faded considerably over time and the idea of trying again started to worm its way back into my head.

This Time Around
So, near the end of 2023 with Orion high in the sky in December, I finally slewed the GTX130 over to the Orion Nebula to start taking data.  As most of you know, in spite of it's popularity, M42 is NOT an easy target!  It's easy to get an image; but it is hard to get a good image!  The biggest challenge is the huge dynamic range so, in order to get a decent result, it's important to use HDR methods to avoid completely blowing out portions of the image.  I selected my "normal" 300s exposures to go after the faint background dust and 180s exposures to handle the brighter stuff.  In hindsight, I probably might have been better off paring the 300s exposure with 90s exposures but the 180s exposures only saturated on the very brightest stars.  I didn't have another project backed up behind this one so I wound up gathering a LOT of data using all of the 7 filters on the scope.  I wound up with about 46 hours of useable LRGB data, which makes it possible to better pull out the faint stuff around the nebula. One other thing that helps is the extremely high quality of the data produced by the GTX130.  It is not uncommon under good seeing conditions to see FWHM stars at 1.2" - 1.3", which is amazing for a scope of this size!  That really helps to produce extraordinarily sharp images.  At some point, I have some projects in mind for the remaining narrow band data but so far, I haven't had the energy to get into it.

I combined the two LRGB exposure sets using the HDRCompsition tool in PI and it did a great job.  The Trapezium is easy visible in the non-stretched data but it was difficult to make it easily visible in the stretched result.  As with everything else, the big challenge lies in getting the colors into the right ballpark.  I used SPCC with the Typical Spiral Galaxy option selected for the white balance.  It  reddened the dust a bit more than I liked so I shifted the color temperature a little bit during final processing in PS to get back to more "dirt-like" colors in the background dust.  

Be sure to zoom in and explore.  There are so many interesting features in this region and I see something new each time I spend some time looking around. This crop is particularly interesting to me.  Look at the round dust "puff-balls" in the lower right that appear to blown from the left.  The visual effect of the nebula in this region is a little reminiscent of extreme close ups of Jovian clouds and the flowing structure reminds me more of a painting than a typical deep sky image.  I think that this image might well stand on its own.



I don't know if I've succeeded in producing a "good" image of M42 but I took my best shot at it.  Let me know what you think.  As I expected, processing a new batch of M42 data was fun but it wasn't trivial!

John


PS The last revision controls the Trapezium region just a little better and if you look carefully you can see the Trapezium stars just barely shinning through.