Re: [photo-3d] hyperstereo of lightening

["John A. Rupkalvis" <stereoscope@xxxxxxxxxxxxx>]

----- Original Message -----
From: "Barwood, Henry L" <hbarwood@xxxxxxxxxxx>
To: <photo-3d@xxxxxxxxxxx>
Sent: Tuesday, January 09, 2001 9:58 AM
Subject: RE: [photo-3d] hyperstereo of lightening


>
> -----Original Message-----
> From: jack.colbran@xxxxxxxxxxxxx [mailto:jack.colbran@xxxxxxxxxxxxx]
> Sent: Tuesday, January 09, 2001 12:49 PM
> To: photo-3d@xxxxxxxxxxx
> Subject: Re: [photo-3d] hyperstereo of lightening
>
>
> Henry Barwood writes...
>
> > I would like to attempt to take some hyperstereo photos of storm clouds
> that
> > capture lightening flashes. My objective is to analyze the lightening
> > flashes in 3D to determine their structure. Does anyone have any
> suggestions
> > how to synchronize two cameras to take simultaneous exposures when they
> may
> > be quite a distance apart? All suggestions and comments are welcome (off
> > list if you find this a boring subject). Thanks.
>
> Henry,
>
> Since you will have to use a longish time exposure, opening the shutters
> just before your estimate of the instant that the lightening will strike,
> surely exact synchronisation is not that important? Couldn't you stand in
> between the cameras and release them one with each hand? (Preferably with
> cable releases.)
>
> I'm assuming that if the opening and closing is not fairly precise, one
> image will have missing/extra stokes from the flash that will be extremely
> confusing. The exact exposure time would probably not be as critical
(except
> to get the proper exposure on the film) as the beginning and ending of the
> exposure. Of course I've never tried this, so have no idea what may
actually
> be involved. I hope to have something rigged up before the Spring/Summer
> lightening season, though.
>
> Henry
>
Good points, except the separation, unless you have very long arms.  I saw
one very good lightning stereo several years ago in which the photographer
had set up two cameras on separate hills quite a distance apart (possibly
miles).  Personally, I would not set up a tripod on a hill during a
lightning storm.  They make great lightning rods...

One other thought.  Since a hyperstereo is a form of abstract photography
anyway, why not be real artsy and do multiple exposures, changing colored
filter gels in front of the cameras between shots?  Might be real
interesting.

JR