Re: [photo-3d] Front surface mirrors

["John A. Rupkalvis" <stereoscope@xxxxxxxxxxxxx>]

----- Original Message -----
From: "David H Quackenbush" <dhq@xxxxxxxx>
To: <photo-3d@xxxxxxxxxxx>
Sent: Monday, January 08, 2001 6:27 AM
Subject: Re: [photo-3d] Front surface mirrors


>
> On Sun, 7 Jan 2001 19:27:00 -0800 "John A. Rupkalvis"
> <stereoscope@xxxxxxxxxxxxx> writes:
>
> >>
> >> Yes, I use beamsplitters, and this sounds like an unbelievably low
> >price
> >(most of the beamsplitters I have gotten have been several hundred
> >dollars).
> >Are these AR coated?  What is the reflection to transmission ratio
> >(equal
> >reflection to equal transmisssion is required for most stereoscopic
> >applications so that both cameras get the same amount of light).
> >
> >JR
> ===================================================
> Hi,
>  The ad only said that the mirrors were used in a laser device. My quess
> is that they were to be used in a barecode scanner.
>
> Regards,  David Quackenbush
>
> ________________________________________________________________
Mirrors???  I am looking for beamsplitters, not image splitters.   Although
beamsplitters are sometimes referred to as "partial mirrors" because the
coating process is similar, they are quite different in function.  A
beamsplitter reflects part of the light (usually less than 50% for
stereoscopic applications) and transmits part of the light (hopefully equal
to the proportion reflected).  Two cameras are then oriented at 90 degrees
to each other (45 degrees incident to the beamsplitter) to achieve the
stereoscopic views with adjustable stereo base.  Are these what you are
referring to?

JR