Re: 116 vs. 716 (part II)

[P3D Eric Goldstein <egoldste@xxxxxx>]

Eric Goldstein wrote:

> aperture differences (in projection lenses) do make a noticable difference in 
> screen brightness
> (a question posed in your part III), easily as much as switching between
> 500 and 750 watt lamps...


In his projection part III, George mentions the brackett dissolvers...

I had the chance to speak with Bob Brackett last month at our Stereo New
England meeting, he was showing his latest handiwork while demonstrating
the beautiful (and somewhat custom!) projector he just made for Jon
Golden...

Bob himself made note of the unfortunate but inevitable loss of
brightness in going from prime 2.8 schneider projection lenses in some
of the first first generation brackett dissolvers to kodak 3.5 zooms in
this new generation... half a stop in projection is quite obvious on the
screen...

The later generation Realist projectors featured f/2.2 lenses (at least
according to the literature, I've never seen one)... this gain of over
1/2 stop over f/2.8 glass, plus 1000 watt lamps must make for a toasty
projection screen!  8-)


Eric G.


------------------------------