Mike "Once in a while you can be shown the light In the strangest of places if you look at it right" - Robt. Hunter
Webster 14.5" f/4.5, "Sugaree" Televue NP 101 (name not yet apparent) Siebert Black Night BVs 8 X 42 Celestron Regals, 12 X 36 Canon IS II
Quote:I just spent 2 nights camping at Canyonlands NP in southern Utah. I think it was in the black zone. However, I was not impressed by the number of stars I saw. I remember being in the Sierra Nevada Mtns. in the winter, and being overwhelmed by so many stars that recognizing constellations was difficult. This was not the case 2 nights ago ...
First and foremost observing love: naked eye.
Last but not least, telescopes.
And I sometimes dabble with cameras.
Quote:The winter sky has a stronger presence of bright stars in my opinion.
Of the ten brightest stars visible from latitude 45N, five (Sirius, Capella, Rigel, Procyon, and Betelgeuse) are crammed into less than 1/10th of the sky, from Rigel (RA 5:15) to Procyon (RA 7:39). This is precisely the area that's visible during mid- to late winter.
Two eyes (5-7mm in full darkness) TS 15x70mm binos TeleVue Genesis 100mm f=500mm Polarex 80mm f=500mm spotting scope (1973) modded and enhanced 2012 GSO 400mm Dob f=1800mm Canon EOS 6 w/85mm f/1.8, 50mm macro f/2,5
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:Actually, we juggle three 'observing parameters' (if I may coin a term here): Sky darkness, Sky Transparency and Seeing. How rare is it to get all three at the 'excellent' level? As we all know, it is exceedingly rare, indeed.Also, Don, what are the extinction units you mentioned (mag/Atmosphere)? And how could an observer measure this quantitatively at an observing session? Dave
Quote:I have seen this as low as 0.15mag/atmosphere in dry air at 8350'.Here is how I measured it, and i will agree with anyone who criticizes the method as flawed, but the method has served me well to compare sites and directional sky brightnesses ...