[cucmbere (Bob)]

Obs: 18/4/09; 18:44 AEST
Equip: 12" f5,6; Radian 8mm; 205X; FOV 18'

A big cloud moved in right on cue and made naked eye sighting impossible but the scope was already positioned on the reference star(Nu Octantis) and then it arrived on cue, maybe 10 arcmin south.

Verdict: speeding bullet, almost 1 second veiwing time and I was off centre of FOV by approx. 5 arcmin! Bright, square shaped? but clouds probably effected seeing more detail. Even so, I just was not ready for it and my eye moved side to side just trying to get a lasting impression of it.

For comparison a 8mm Ethos e.p. would give a FOV of half a degree which is 6 arcmin. less than the last obs. made with the 12mm Nagler e.p. and 12 arcmin. more than the 8mm Radian e.p. The obs. made with the 12mm was much more comfortable with the larger FOV(36'). It is the amount of time required for the eye-brain to connect to the visual cue that is required for the brain to get a lasting impression.

Since I dont have an Ethos i will use a 20mm Nagler and 2X Barlow yeilding 164X and 0.48 degrees of arc(28,8').


Bob.