Seeing v's Transparency

[ballaratdragons (Ken)]

OK, you have my curiosity aroused. Many of you keep referring to Seeing 7/10 and Transparency 8/10.

I get the 'score out of ten' bit, but what's the difference between 'Seeing' and 'Transparency'?

I would've thought them to be the same thing. To have good seeing you must have good Transparency!

See, 20 years at this and I still don't have a clue. By the way Houghy, I gotta ask, are you writing a book in your signature? It takes about 20 minutes to read it. I hope the sequel is better!

[h0ughy (David)]

Thanks for asking the Question Ken, I'd like to know too about transparency. Who is awake to teach us!

BTW what wrong with the signature. OK I will modify it Just for you Ken

[asimov (John)]

http://www.astromax.com/aaaa/faq/aa01faq14.htm

[ballaratdragons (Ken)]

Thanks John. Sounds too confusing for me though. I think I will stick to saying things like "everything was 7/10".

[RapidEye]

Here are a couple more links:

http://www.weatheroffice.ec.gc.ca/as...parence_e.html

http://www.weatheroffice.ec.gc.ca/astro/seeing_e.html

They use a 1-5 scale, but same theory applies.

Think about it this way guys:
Transperancy is a measure of how much crud is in the air. More crud (dust, smoke, humidity) the less faint things you can see: nebula and galaxies.

Seeing can also be referred to as steadiness. You can have crystal clear skies, but if the jet stream is screaming overhead, the image will be all jumbled like the air over hot asphalt. The steadier the image, the better for planetary and/or double stars.

The effects of transperancy can be negated by light pollution or the moon; however, seeing isn't. But good seeing can be negated by doing something silly like looking over the roof of your house in the middle of a cold night.

Hope those links and thought help!

[gaa_ian (Ian)]

Oh ... now I understand
Thanks for the links, though

[asimov (John)]

Yeah, these days I use the good old 'how much is a star twinkling @ 45 deg above the horizon' to ascertain weather I bother setting up or not. Good explaination rapid. I was too lazy to type all that, lol.

[ballaratdragons (Ken)]

Um, yep.

Glad I'm not the only one who doesn't know the difference!

[asimov (John)]

Seeing it's been raining here for 2 days straight & washed all the crap/dust etc. out & now it's clear....I have 7 outa 7 transparency!!

[RapidEye]

No problem fellas.

I just had one more thought....
Tube currents in your scope can easily be confused for unsteady skies (poor seeing).

G'Luck!!!

[h0ughy (David)]

Originally Posted by ballaratdragons

Um, yep.

Glad I'm not the only one who doesn't know the difference!

You are quite correct Ken, you and I don't know any different , Except you have a very large signature that is riduculous

[h0ughy (David)]

Originally Posted by RapidEye

No problem fellas.

I just had one more thought....
Tube currents in your scope can easily be confused for unsteady skies (poor seeing).

G'Luck!!!

Thanks Rapid Eye

[janoskiss (Steve H)]

In a nutshell:-
transparency: how much light the atmosphere transmits.
seeing: how turbulent the atmosphere is.

[RAJAH235]

Ahh Steve. KISS, eh? L.

[RapidEye]

And a picture is worth a thousand words

[xstream (John)]

This is a good link for seeing

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

[ving (David)]

interesting topic. of course i am brilliant and knew it all already.
actually i think theres been another thread named the same thing.

actually at the bottom of this page theres links to 3 threads covering seeing vs trans.

its all good!
some times i post for the sake of it

[janoskiss (Steve H)]

Originally Posted by ving

actually at the bottom of this page theres links to 3 threads covering seeing vs trans.

[asimov (John)]

99 to go vingster...

[ving (David)]

98!
dont encourage me asimov!