Spent an hour in the back yard with the 12.5-inch. I planned to just hop double star to double star for a leisurely evening; it's been a while since I've done that. But the seeing was quite poor: bloated stars even at just 170x. I believe it was tube currents, in spite of my fan. The air temperature drops 20 degrees once the sun sets, and it still takes a few hours for the mirror to equilibrate, fans or no.
So I had a look at low power, mainly at M42 the Orion Nebula. It was very bright and green color, with streaks of red/pink color on the "fish's" back. Plenty of mottling, and the trapezium was plain, if only resolved to four stars. Great arcs of nebulosity extending around the fish. I put on a UHC filter since people rave about it; the sky was darker and the nebula more defined with the contrast, but the stars turned an artificial green color. I much preferred the unfiltered view.
High bands of cloud moved in, and the poor seeing made me decide to pack it in earlier than I hoped. I'm still a bit tired from waking early these last two mornings. I'll have to tell my body to let me sleep late tomorrow morning.
It's supposed to be rainy the next week, so this might be the last session for a while.