George N Obsession 20 Optical Guidance Systems 10" F/9 R-C Cass 6" F/5 & 8" F/8 home-made Newts Explore Scientific 127mm ED MI-250 mount Denk II bino-viewer, with PowerX and Newt reducer, Member, International Dark-Sky Association
Quote: The height advantage of the refractor on a taller mount becomes more of a factor on smaller observing fields. Something to ponder.
Quote:If we assume a distance to the tree line of 100 feet, a 2 foot gain in height results in an angular gain of a massive 1.15 degrees!Sarcasm aside, typical variations in mount height count for little, unless the obstructor is quite nearby.
Quote:At an observatory that one of our members manages, he has calculated that the telescope inside should be raised, the pier is too short. Given the lower boundary of the slit opening, raising the pier one foot will give us an additional 7 degrees of sky below the current cut-off. That is significant!
7x35 and 10x50 sears tower binocs, 3" f/10 edmunds reflector, 2.4" f/11.7 manon refractor, 6" f/8 jaegers refractor, 10" f/11 R30 Istar refractor, 3" f/15.8 sans&streiffe refractor, 3.1" f/15 selsi refractor(towa 339), 2.4" f/15 sears refractor, selsi 30x30mm spyglass, criterion 5-draw 25x45x75x spyglass(1957), 4.25" f/14.8 tasco 20te.http://cleardarksky.com/c/OmahaNEkey.html
Quote: With my home ROR observatory I've always taken the stance you live with what you have. I've developed the "let it come to you" approach. I'm spoiled rotten with my big refractor sitting on the west side of the pier. I can easily see things rise in the east and follow them into the SW sky.
Quote:Why not just build a concrete platform with steps and move the observatory up.
Quote: As hinted at before, I was just pulling the chain a little bit for some of our dobsonian friends.Barry Simon
Quote:Of course down your way, the highest point in the entire state is only 525 feet above sea level... Around here that's not even a hill.. Jon
Quote:Yes, but our coastal skies are quite steady. Exceptional planetary seeing is the rule, not the exception. As far as the mosquitoes go....they are our friends. We attach little cleaning pads to their feet and they keep the dew off of our objectives.Kidding aside, we do appreciate higher altitude. In the first week of September I am going to my sister's getaway about 10 miles south of and 1300 feet above Gunnison, CO. We will be observing from 8960 feet. So I think we will have the height we need without getting into the "Goofy Zone". At least goofy beyond what is normal for me.
Quote:Quote:Why not just build a concrete platform with steps and move the observatory up. The pines are growing at the rate of 12" to 18" per year. Do you suggest that we raise our observatory every year by that amount? Barry Simon
Quote:So basically we responded with answers to help you with the decision only to find that we were basically wasting out time.
Thanks for that.
Quote:George, how high does a ground-level boundary layer of hot air typically extend? I imagine that variables like altitude, season and the nature of the ground all play a role.Your comments got me doing a bit of research and I found a PDF file that is interesting. I think it gives some detail to what you are talking about (ground level boundary layer). Here it is: http://www.envirocomp.com/airpollution/Ch.3.PDFPerhaps someone else can reinterpret this and rephrase it in a meaningful way for everyday utilization in selecting observing sites.Barry Simon
I lost count of my scopes. Now I just want mobility. I came, I saw, I bought some interesting accessories, and put names to faces: NEAF 2012, ASAE 2012, SWAP 2013, ASAE 2013.
Quote:What you really need to do is have more than one event at Percy Quinn each year. Those skies were nice. -Rich