Re: 3D Separate 2x2 Projection

[P3D John Bercovitz <bercov@xxxxxxxxxxx>]

Greg Wageman writes:

> Is anyone on this list using independent 2x2 projectors?

I'm sure there is, but not I.  8-)

> I'm currently using the "stock" projection lamp (FHS?), but am thinking
> about moving to the EXR lamp, which is supposed to be much brighter, at
> half of the rated life.  

I don't have the light output figures for these lamps but here's what
I do have:

All are 82V
part no  power    life     color temp
  EXW    300W     15 hrs     3450K
  EXR    300W     35 hrs     3350K
  FHS    300W     70 hrs     3300K
  EXY    250W    200 hrs     3200K

> However, I've seen traffic on this list that
> suggests that this may be a liability rather than a benefit, due to
> increased "ghosting".

Well, that will be a function of the screen brighhtness which will be
a function of your lamp choice, the condenser optics, projection lens 
f/number, the transmission of the Polaroid filters, the screen reflect-
ance, screen distribution, and screen size.  For a good discussion of 
this somewhat detailed-filled topic, see Kingslake's "Optics in 
Photography".

John B


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