[ngcles]

Hi John & All,

John wrote:

"The most recent was in October 2007 at Coonabrabran when we experienced excellent conditions. I obtained regular repeatable readings of between 21.85 and 21.9 on my Unihedron Sky Quality Meter."

As a matter of interest, I was up at Mudgee (Gratti) for the last several days (only got one good night).

On that night (Sat 29112008) at 11.30pm I got readings on my SQM/L (my method is to take four readings, discard the first and average the following three) of 21.88, 21.90 & 21.90 making an average of 21.89. On this reading run it beeped between 12 and 13 times before readout (lots of beeps means lots of dark).

The "worst" averaged reading I got for the night was 21.84. The best single reading (not a first reading) was 21.91.

This equates to a ZLM of about 6.6. M33 was just visible naked eye. The Milky Way was incredibly detailed, marbled and dozens of O.Cs visible naked eye. At one stage I counted 14 stars in the area bounded by Betelgeuse, Bellatrix and the belt stars of Orion. It was a very, very good night -- I spent half of it gawking (slack-jawed and dribbling) naked-eye. I'd say it was a Bortle 1-2.

I love my SQM if only because it is totally objective provided it is used in accordance with the manufacturers instructions and people don't "gild the lily".

Best,

Les D