David Cotterell Toronto, Ontario "If an observer actually sees an object, there is no point in referring to a formula to find out whether he ought to see it; and if he fails to detect it, no formula will ensure his success." - W.H. Steavenson 8" f/15.5 TEC Maksutov 16" f/5 Teeter/Zambuto Dob 66mm WO SD AT 65EDQ APO Refractor Astro-Physics Mach 1 GTO Mount iOptron ZEQ25 mount Canon 60Da
Quote: Transparency is NOT Seeing
Orion XT12i with Swayze-refigured primary & Protostar secondary
Televue NP101 refractor
William Optics Megrez 90 refractor
Universal Astronomics Deluxe Mounts
I have four awesome refractors representing their eras of design and productionAstrophysics-Tinsley (I can't afford anything beginning with Z)
Quote: ...providing an unpleasant view.
"I have been paddling in the shallows of a great ocean of knowledge." - Sir Isaac Newton * * 15" F4.55 Starsplitter Dob & a Denk II binoviewer * * http://peaceofsky.wordpress.com/ Pacheco State Park Fremont Peak
Quote:The water in the stream can be crystal clear and free of particulate matter;however, if there are ripples on the surface the bottom of the stream will appear distorted providing an unpleasant view.
I'd rather be driving my .
Meade LS8 ACF Meade 2" Diagonal Apetura 10" Tweakers Package Meade ETX-125, ETX-90 for Solar Celestron 80mm APO PST Meade SWA - 34mm,28mm,24mm,20mm Brandon 32mm, 16mm Vernonscope 40mm Erfle 2" ES 14mm,11mm,6.7mm 8.8 Nagler 13mm T6, Pan 19mm Meade 12.4 Pl,9.7mm, 15mm SP Meade 2x Shorty Barlow Powermate 2.5x WO Bino Viewer, 20mm 66* pair Denkmier 2 Super System Meade Nebula Filters Meade 9x60 Bino Vivitar S1 8x42 Bino Canon T2i, 18-55mm, 50mm 1.8, 55-250mm
Quote: Transparency is about the degree to which the atmosphere dims the image due to humidity, dust, thin cloud, smoke, contrails, particulate matter and what have you. The amount of light getting through, I suppose.
Quote: Quote: Transparency is about the degree to which the atmosphere dims the image due to humidity, dust, thin cloud, smoke, contrails, particulate matter and what have you. The amount of light getting through, I suppose. I've often thot that the "blueness" of the sky during the day is a measure of the air's "transparency", and if unchanged into the night, would yield the better deepsky views.Is this a fair analysis?
Quote:and darkness is not transparency. Rant over in reply Bill in Flag
Quote:Yeah, always used that asumption from when I was a kid just starting out, most times it seems to work....BUT I have seen those deep blue skies all day just to give way to clouds after sunset!Also I use a small mountain in the distance from where I live and if I can see the tree detail I know it's going to be a good scope night:)
Paul B. Jones http://www.astrobin.com/users/bunyon/
Quote: Shorter or non-existent contrails can be an indicator of dry air in the upper atmosphere.
Scopes: CPC8, TV85+Voyager Binos: 40-70mm, GT80mm~45deg
"We live in the sky, not under it." John Tyndall