Re: image brightness

[P3D John Dukes <dukes@xxxxxxxxxxxxxxxx>]

My take on projection brightness, ghosting, etc.: Use the brightest
illumination system you can get, without frying your slides, and use
the the most effective polarizers you can get. (But) there is a very real
tradeoff: More transmissive polarizers don't null as well. So if you
have a chance to pick your own material, you have to decide what's
important.  If you take pictures with high contrast you may want
the better null and reduced transmission.  But remember that the 
final null depends on both projection polarizers AND the polarizers in
your glasses, so you have to consider the combination.

Once you have your materials, your machine, and your slides, you can
reduce the apparent ghosting, if you feel the need, as I suggested
in an earlier post, by bringing up the background roomlight SLIGHTLY
to to cover it up.

John Dukes


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