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Lightningwizard · 登録日: 2007.10.19 記事: 165

http://eurosprite.blogspot.com

I captured this last night from my village, 40 km northwest of Barcelona Shocked

Oscar

SonotaCo · 日時: Thu Jul 03, 2008 7:50 am 記事の件名: Re: Sprite 1-2 July, Spain

Oh beautiful Shocked

. There are more than 30 columns Exclamation

.
More over, very long tendrils are imaged clearly.
In my understanding, tendrils can be imaged only from near station
because their spectrum(almost blue?) decays faster than red columns.
How far is the event?
Could you let us know your equipments?

Lightningwizard · 登録日: 2007.10.19 記事: 165

The event was about 209 km away (+CG lightning location), imaged with Watec 902H2 Ultimate, MGC, gamma HI, Computar 12mm F/0.8.

Setting gamma to HI enhances dim parts of an image, like stars and tendrils, without affecting much the bright parts. Moreover, I have found that at the same MGC gain setting, the gamma OFF and LO clip the highlights more than the gamma HI setting (test this with the moon behind clouds, for example). But if you operate the camera with this setting in a very light-polluted area it will make the sky look ugly bright.

Not sure the tendrils really have large amounts of blue, maybe only significant if lower than 50 km...

Oscar

SonotaCo · 日時: Fri Jul 04, 2008 10:13 am 記事の件名:

Hi Oscar, thank you for info.
I was thinking the event was much nearer because the tendrils are so beautiful.
I agree with you about gamma, though I could not test it because the sky of Tokyo is very bright.

Anyway, thirst for goof color camera is increasing year by year.
It exists, but is far beyond our reach.
http://www.emccd.net/ (almost 5,000,000 Yen > 30,000 EURO)

SonotaCo