18" Classic Obsession w/ ArgoNavis & ServoCAT 120mm Orion Sky View Pro refractor
AD10, NoName8, DS-16 with Spooner primary.
ES, Sterling, Parks, Baader, TV, GSO EP's and a lone Nagler.
Nikon, Celestron binos
Quote:Roy, I'm just south of you and had the same experience a couple nights ago. The temperature alone isn't the cause. The problem has been the unusually high humidity - dew point within a degree or two of the temperature. It's been getting slowly better the last couple evenings, as the recent snow melts off, from 88% RH to 75% last nite to 69% tonite. All much higher than we're accustomed to up here.I highly doubt that a couple nights of frost would damage the coatings.
Quote:For ice crystals to form in air, the air temperature would have to get down to well below -20C, or several degrees below 0F. Warmer than this and you have water droplet mist, or fog when dense enough. In either case, a GLP beam would scintillate with a veritable blizzard of quite brilliant sparkles.
Quote:My question is: Would just frost alone damage the coatings?
Roy in Taos
10" F/4.7 Modified Skywatcher Reflector, 38mm Orion Q70, 17mm Modified Ultima LX, 10mm TeleVue Delos, 7mm Pentax XL.
Quote:Quote:My question is: Would just frost alone damage the coatings?Thanks,Roy in TaosHe's not looking for a lesson in weather or Physics, he just wants to know if it will damage the mirror or not. I've had it form on my mirror dozens of times, and my mirror still gives excellent images of planets, globs etc.. Just leave the top cap off of your mirror for at least 4 hours and then re-cap it. The only thing I would be concerned about is repeated condensation from "acid dew".....If it gets really bad over the course of so many years, get a re-coat or a new mirror.Weather eventually takes it's toll on many things.Take a good look at my mirror. I got it this way through a trade and I have still been using it for my third year and images are still really good. (It has been cleaned by me 2 times. The original owner used the wrong Alcohol type which left blue streaks...or the coating it failing).
Quote:My question is: Would just frost alone damage the coatings?Thanks,Roy in Taos
Quote:Absolutely. Seeing has been good (relatively still air) but the humidity has really taken a toll on transparency, scattering light from any source and whitening the background. Not fun for DSO hunting...
Quote:I just got inside from a 2-hour galaxy-observing session. I began with NGC891, which still looked fuzzier than usual, although better than a few nights ago. Other galaxies in the Perseus and Pisces clusters were clearer, but they were also nearer the zenith. Galaxies closer to the horizon, like NGC1232 and even M33 were hazy.