Re: Beading caught on film.

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve.conner@xxxxxxxxxxx>

At 19:04 03/05/05 -0600, you wrote:

> Don't know what it is...

I think it's a length of arc channel that heads directly away from or 
towards the camera so you're looking right down it. That makes it seem 
brighter. You wouldn't see that with the eye because you have two eyes and 
see in 3-d.

On a related note, a while back I saw a post where someone saw two dark 
bands in a plasma tube (powered by a NST) that he photographed with 1/250 
sec shutter speed, so assumed that they couldn't be due to zero crossings 
of the 60Hz. He went on to assume that this was caused by some sort of self 
organising plasma.

Well I recently found out that this can happen with SLR cameras that have a 
focal plane shutter. The actual shutter blinds move quite slowly and fast 
shutter speeds are achieved by narrowing the slit between them. So a given 
piece of film may only get exposed for 1/1000 sec but it can take 1/60 sec 
to expose the whole frame. Hit google for an explanation of the focal plane 
shutter.


Steve Conner