Green Flash

[Tim N]

I was reading an interesting article about "Green Flash" where, when the sun is setting the very top edge can sometimes appear green just as it slips below the horizon. It can also happen at sunrise.
How would you go about capturing something like this ? I am thinking perhaps with a pretty strong ND filter (not grad) but still a fairly fast shutter speed and perhaps shooting a few frames as the sun is setting / rising.
It doesnt happen everyday and apparently the sky needs to be very very clear before this "green flash" will appear. I have attached a NASA url which has some pictures and in depth explanations on how and why this occurs.
Has anyone actually seen this happen ? Also you can sometimes see a "Blue Flash" which is apparently even more rare than a Green Flash but the sky has to be exceptionally clear.
Does anyone have any ideas on how to get a picture of this ? (it only lasts about a second)
http://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search?green+flash

[JohnP]

Hi Tim.

This is very interesting, but it seems you need a bit of height as the published shots seem to be taken from mountain tops.
Good hunting with this one and I look forward to the result.

Best,

John.

[Analog6]

It is very hard and comes about more by luck than judgement.  There have been extensivce discussions about it on my Solar Eclipse webmail list, and a few have acheived it.

You don't have to be high, it has been done at sea level from a beach.  Atmospheric conditions have a lot to do with it.

Here's teh Wiki entry: http://en.wikipedia.org/wiki/Green_flash

[Tim N]

It is very hard and comes about more by luck than judgement.

Atmospheric conditions have a lot to do with it.

This is basically what I picked up from the websites I looked at as well ! I was up for a cycle early today but forgot to look for the sunrise ... happens at 45km/hr on a bike