Re: [Leica] Measured Reaction Time / Marvin / Alf / Dave

["Alan Hull" <hull@vaggeryd.mail.telia.com>]

Ted and Donal,
I spent a week capturing the mythical green flash, from a beach in the
Carribean.  My technique used the curvature of the earth to assist reaction
times.  I only tried it with sunsets, in fact I didn't know it was also
present at sunrise.  Apart from that, my yacht and the beach were on the
west side of the island, so sunsets were what I had.  From the beach, if
you sit on the sand, the horizon is about one mile away.  if you stand up
the horizon is over two miles away.  Thats the key.  Set the camera up on a
high tripod,  then sit on the sand (a chair is more comfortable).  When you
see the green flash, release the shutter.  You can calculate the difference
in time if you want to make your head hurt,  refraction complicates the 
equation, or you can experiment.  Wait for the rim of the sun to kiss the
horizon then stand up and count the seconds until it happens again.  

Did I succeed.  Dont know.  Because of the humidity I stored the film in a
tin surrounded by dry tea leaves.  That tin and a whole heap of tinned food
was stolen from the boat a few days later.  I was lucky because the cameras
and radio gear were not even disturbed.  

When I discussed this with a boffin in a white coat with his top pocket
full of pencils he told me the green flash was only a sensory thing caused
by the sudden removal of a bright red sun from the retina of the eye,
causing a neuron backlash. 

One day I will try again.  Dont forget the ND filters over your eye.  I
used sextant shades.

Alan Hull
- ----------
> 
> I have watched for, seen it and tried to shoot it so many times I've lost
> count. I don't think it is humanly possible to see and shoot at the same
> time, whether you are using an M or R, EOS or NIKON! If anyone has seen
the
> green flash and actally had reflexes fast enough to get it on a stills
> frame, it has to be 200 % pure luck.
> 
> I've seen it on movie film with a pro crew running high speed cameras,
only
> because the camera was rolling before the sun broke the edge of the
> horizon.
> 
> I wasn't aware of the "green flash" until I read an article in Readers
> Digest a very long time ago and ever since, whenever there is the
> opportunity to photograph a sunrise over water I have tried to capture
it.
> 
> I trust everone out there in LUG land knows about the "brilliant green
> flash" just as the sun breaks the horizon, quite beutiful, but I bet
rarely
> captured on film, Leica or not! :)
> 
> So you missed it eh?  Gee after all these years I now feel better,
because
> a buddy admitted he missed it also. :)
> 
> ted