Well, according that map:
Observatory Hill (Sydney) 18.16 and Bortle 8-9;
At my place it’s 20.37 and Bortle 5;
15 minutes away the NSAS site at Terry Hills is 20.56, Bortle 4;
Two hours drive to Shipley Plateau - 21.78, and Bortle 3 which is understandable with the sky glow from Sydney in the east.
Eight hours drive to Mt Kaputar - 22, and Bortle 1.
IMHO the Bortle scale is more meaningful as across these locations the SQM value varies by only 3.84 (and to be quoted 4 significant figures is frankly absurd when measuring sky brightness) whereas the Bortle values range from 1 to 9.
Last edited by Wavytone; 06-01-2019 at 10:21 PM.
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