Thread: Share your SQM?
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Old 06-01-2019, 11:33 PM
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ngcles
The Observologist

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Join Date: Dec 2006
Location: Billimari, NSW Central West
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Hi Wavytone & All,

Quote:
Originally Posted by Wavytone View Post
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.
But, the magnitude scale is a logarithmic one -- with each whole step being effectively 2.52 times fainter than the preceding whole step. Whereas, the Bortle scale is linear, so the reality is ... (I'll let you find a pencil & an envelope).

Best,

L.