Tonight I had one of the top 3 most transparent nights I've had from my backyard observing location.
It seemed like all my eyepieces had O-III filters on them. The football shape of M27 with converging shell wisps was very obvious. Those wisps *almost* touched even without the O-III filter. Adding an O-III brought the outer extents of the football into clear view at 214x.
Swinging over to the Cat's Eye Nebula (NGC 6543), I don't know if it was my imagination, but it looked like you could see the outer shell glowing very faintly around it at 571x
The Fireworks galaxy NGC 6946 showed very faint but visible spiral structure in averted vision at 137x.
The southern edge of the North America nebula was strikingly obvious in an OIII filter and 28mm RKE. The Gulf of Mexico region was sharply defined. I had never realized how easily this object could be seen. I actually wish I had a smaller rich field instrument for it.
The Veil was was incredible. I spent about an hour with it. Never saw so many knots and wisps and tendrils before. I desperately need a modern 2" O-III!
M17, M8, and M20 with O-III were incredible. I've never seen such strong definition in the Trifid before. The Swan was just a small part of the mass of nebulosity I could see in M17. M8 was loaded with well defined structure.
The central star of M57 was far more intermittently visible than it has been, even with mediocre seeing.
The Draco Group and several other Draco galaxies were strongly pronounced.
M81's brightest star cloud was obvious, though I could not quite see a well defined spiral structure due to the low altitude it was at at the time of observation.
M31's dual dust lanes were very high contrast tonight, in spite of its low altitude in a light polluted area of the sky. The bright star cloud on the western side of the galaxy was also obvious. Would have loved to have seen this at the zenith. Guess I'll have to wait until late September.
The Milky Way in general was almost distractingly beautiful. I had to force myself to look through the telescope tonight