RE: [photo-3d] hyperstereo of lightening

["Barwood, Henry L" <hbarwood@xxxxxxxxxxx>]

-----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