Transperancy rating

[Kal (Andrew)]

I've read the article on rating seeing/transperancy on the IIS "Projects & articles" section found here and the system used is one where transperancy is rated from 0-7. However, I never see people rate transperancy on a scale of 7.

My question is, what other transperancy scales are out there in use and where can I find transperancy scales from 0-5 or 0-10 which I can correlate these ratings against?

[JohnG (John)]

Here is a link to the Pickering Seeing Scale:

http://uk.geocities.com/dpeach_78/pickering.htm

Cheers

JohnG

[Kal (Andrew)]

Hi John,

I've seen the pickering scale before, and Damian's webpage demonstrates it perfectly, however, the pickering scale is a measure of seeing, while I am interested in seeing scales of transperency.

[Kal (Andrew)]

bump

[ving (David)]

hmm... from here (but this is nh)
http://www.astromax.com/aaaa/faq/aa01faq14.htm

TRANSPARENCY SCALE

0. Do Not Observe - Completely cloudy or precipitating.
1. Very Poor - Mostly Cloudy.
2. Poor - Partly cloudy or heavy haze. 1 or 2 Little Dipper stars visible.
3. Somewhat Clear - Cirrus or moderate haze. 3 or 4 Little Dipper stars visible.
4. Partly Clear - Slight haze. 4 or 5 Little Dipper stars visible.
5. Clear - No clouds. Milky Way visible with averted vision. 6 Little Dipper stars visible.
6. Very Clear - Milky Way and M31 visible. 7 Little Dipper stars visible.
7. Extremely Clear - M33 and/or M81 visible.

[ving (David)]

or try this:
http://www.sctscopes.net/Observing_w...ncy_Scale.html

[ving (David)]

or john bortles article on s&t

http://www.skyandtelescope.com/resou...tml?page=1&c=y

[Kal (Andrew)]

Originally Posted by ving

or try this:
http://www.sctscopes.net/Observing_with_an_SCT/Learning_to_See/UMi_-_Viewing/SAC_Transparency_Scale.html

Thanks ving this is exactly what I wanted!

My googling skills aren't what they used to be