Re: Now released: Peter Goldie's 'corkscrew lightning' photo of Columbia entry

From: Alan Baker (alangbaker_at_telus.net)
Date: 02/25/05 

Date: Fri, 25 Feb 2005 20:13:43 GMT

In article <cvnh1g$lvn$1@scotsman.ed.ac.uk>,
 Angus Rae <Angus.Rae@ed.ac.uk> wrote:

> Jim Oberg wrote:
> > Ignore the mega-lightning gobbledegook from the crackpot URL,
> > but think about whether the 'bumped camera' explanation makes
> > any more sense?
>
> Actually, I think it does. It does depend if this was a film or digital
> camera, but - assuming film - it looks to me like a double exposure.
>
> My guess is that the shutter was opened when the Shuttle was 1/4 of the
> way across the frame and the camera was bumped in the process, causing
> the wiggle as the shuttle proceeded from left to right across the frame
> (in fact it looks like the shutter was opened as the camera was being
> aimed - the varying brightness of the wiggle looks like the motion was
> driven by muscle motion rather than a "bump"). The camera was then
> steadied, and a straight trail was produced across the last 1/2 of the
> frame.
>
> The photographer then closed the shutter, re-aimed the camera to take
> another shot, and re-opened the shutter again without winding on
> (probably forgot). This time there was no bump and the camera captured
> the shuttle moving from left to right once more. By coincidence
> (although the photographer was likely trying as many times as possible
> in his viewing window for the same appearance of picture, so it's not
> really a surprise) the trail of the second exposure almost matches up
> with the first exposure over the second part of the frame. It looks to
> me as though it's not _quite_ aligned, and hence the trail looks thicker
> as well as brighter once the two trails overlay each other.
>
> Note I'm not a photographic expert, so this is purely what it looks like
> to my (untrained) eye. I have taken a few bad photographs though!

I find it hard to imagine that the two trails could align that closely
if it were two shots taken one after the other, but how about this:

The shutter is opened just before Columbia enters frame and it remains
open for it's entire transit.

Following just behind Columbia is a piece of something that's already
broken off and is on the same track (naturally) and as it passes through
the frame, the camera is bumped. 

-- 
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."

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