Finally I had a beautiful clear night, even in the Florida summer, to try out my converted Canon M200 for one of things I got it for: astrophotography! I had to go out at 2 AM... it had rained and everything was soaking wet, but it was worth it!
I used the full-spectrum-converted M200 on a SkyGuider Pro star tracker and tried different lenses and filter combinations.
After a few trials I settled on shooting with the Spencer Camera Visible + hydrogen-alpha which allows the visible spectrum and near-IR but blocks around 700 nm and longer. I stacked that with the K+F Concept Clear-Natural light pollution filter (from Amazon) which appears to be quite effective in handling the light pollution from my shooting location in Tarpon Springs on the Gulf of Mexico. All shots below with the M200 were taken using both those filters stacked.
The summer Milky way, with the manual Rokinon 12mm f2 lens in native EF-M mount:
Ultra-wide summer Milky way from Cygnus to Sagittarius. Full-spectrum Canon M200, K&F LP filter, Spencer camera Visible + Ha filter, Rokinon 12mm f2 lens, f2, 30 seconds, ISO 100 (!)
Rich Milky Way star field in Cygnus, and the North American Nebula upper right corner. Full-spectrum Canon M200, K&F LP filter, Spencer camera Visible + Ha filter, Rokinon 12mm f2 lens, f2, 30 seconds, ISO 100, cropped center of frame
The Milky Way images show far more 'richness' and a lot more 'red' in Visible + Hydrogen-alpha light than they do in plain visible light. The dark 'coal sack' nebulas in Cygnus and the dark lanes through the galactic core (to the lower left in the first image) don't appear so dark, they must be giving off a good deal of IR light.
Images with the EF manual Rokinon 135mm f2 & Canon EF to EOS M adapter:
Trifid and Lagoon nebulas, and a globular cluster. Full-spectrum Canon M200, K&F LP filter, Spencer Visible + Ha filter, Rokinon 135mm f2 lens, f2, 30 seconds, ISO 400, cropped at pixel res
2 globular star clusters in Sagittarius. Full-spectrum Canon M200, K&F LP filter, Spencer Visible + Ha filter, Rokinon 135mm f2 lens, f2, 30 seconds, ISO 400, cropped at pixel res
The Dumbbell Nebula in Cygnus. Full-spectrum Canon M200, K&F LP filter, Spencer Visible + Ha filter, Rokinon 135mm f2 lens, f2, 20 seconds, ISO 800, cropped at pixel res
The Ring Nebula in Lyra. Full-spectrum Canon M200, K&F LP filter, Spencer Visible + Ha filter, Rokinon 135mm f2 lens, f2, 30 seconds, ISO 400, cropped at pixel res
Another image of the Ring Nebula with an unconverted Canon M6ii, using the EF-S 55-250mm IS STM lens, plus my home-made 2x MC7 teleconverter with vintage Kiron optics, with no filters on the lens. 20 separate 1-minute-long exposures on the star tracker at 500mm/f11/ISO 1600, stacked in Deep Sky Stacker with flat and bias frames to make a single 20-minute exposure. Sharpened in Registax with wavelets, final processing in DxO Photolab 5:
The Ring Nebula in Lyra. Unconverted Canon M6ii, Canon EF-S 55-250 IS STM, vintage Kiron 2x MC7 teleconverter, 500mm, f11, ISO 1600, 20 exposures of 1 minute each stacked with Deep Sky Stacker
Notice the Ring nebula appears an aqua color in the unconverted camera, this is from the green emission lines given off by the gas in the central nebula. In the other visible + hydrogen-alpha light image, the outer parts of the nebula appear orange-yellow from the H-alpha emissions that the unconverted M6ii can't see almost at all.