John Iramiyan's M16, the Eagle Nebula in narrowband
Just take a look at this photo of M16 - the Eagle nebula.
The Pillars of Creation are right in the centre of the image, and to the left there's the Stellar Spire. Note the horseshoe shaped structure at the top of the nebula - I'll get back to that.
John uses a saxon 127mm FCD100 triplet refractor. This is one of the big ones.
For an imaging array, John uses the popular ZWO ASI1600MM-Pro monochrome camera and shoots through narrowband filters. All his exposures are four minutes long.
John has presented his image in the so-called "Hubble Palette", where images taken though the Sulphur filter are shown as red, those taken though the Hydrogen alpha filter are shown as green and those taken through the Oxygen filter are shows as blue.
As a contrast, here's one of my own photos of M16. It's taken with similar equipment, an ASI1600MM-Pro, a slightly smaller 107mm triplet refractor and narrowband filters, which are presented using the Hubble pallete. It's immediately obvious that John's image is very, very good.
First, John has turned the green down a lot more than I did. this is because Hydrogen (which shows up as green in the Hubble palette) is very dominant, as Hydrogen is the most abundant element, and is actually pink. While I personally like the blue-green look, John's representation is closer to reality.
Second, I really like the high contrast in this photo - the deepness of the shadows and the sharpness of narrowband gives the image a threatening and moody feel, as well as enhancing the 3-dimensional effect. It looks like we're peering into a cave.
Third, John was able to get detail that I missed. Compare those horseshoes.
I also like the unobtrusive stars. My stars are too big, too white and too numerous. They detract from the nebula.
John removed the stars, processed them to make them about 30 percent smaller and then replaced them. The same number of stars are there as in my image, just a lot smaller.
Every astrophotographer knows the places where they can improve. I'm sure John has a list of things to do with his next photo, but I can't see any major problems here.
It's a great photo, John, and well processed!