From: "Richard Schwartz" 
To: 
Reply-To: "Richard Schwartz" 


I did some consulting for Kaiser a long time ago, and I think I know what
you have.  It is most likely a projector lens for a heads-up-display
system. The large size indicates that it is intended for a large transport
aircraft; the lenses for fighters are much smaller.

One variable in the design of such optical systems is the shape of the
focal plane.   It is advantageous to use a curved focal plane, and then
manufacture the CRT projector tube to match or use a flat faced tube with a
fiber optic field flattener.

Keep in mind that in the intended use, the pupil in use is limited by the
human eye.  It is never intended to form an image from the entire lens.

So the best use of that lens is as a superb reflex sight for a large
telescope... especially if you can make an illuminated reticle whose
curvature matches the focal plane of your lens.

CRT displays are now being obsoleted by other technologies: LED's, plasma,
laser, etc.   A tough requirement is for the 10,000 ft-lamberts you need
for
visibility in sunlight.  Modern signal processing electronics and large
capacity memory chips make it easy to process the nasty FLIR video format,
so everything in the display world is getting better, lighter, faster, and
cheaper.

. . . Richard



----- Original Message -----
From: "David Lonard" 
To: 
Sent: Friday, May 02, 2003 12:10 PM Subject: ATM A large refractor experience


>
>
>
> Dear Group,
>
> I would like to relay my experience concerning the
> impulsive purchase of a large Kaiser Electro Optics
> surplus objective that I obtained from
> Surplus Shed for others that may get their hands on
> one of these.  It has 11" clear aperture
> and is stated to be a triplet oil spaced f/3.3 objective.
> The outward facing side is strongly convex while the
> side facing the eyepiece is less strongly concave.
> Ronchi star testing revealed very straight lines,
> so it appears to be well corrected for viewing
> objects at infinite distance.  The down side is
> that is displays considerable chromatic aberration
> on bright objects, jupiter had a nasty violet halo
> around it, although it does resolve detail down to
> about as well as southeast Texas skies will allow.
>
> As for its more realistic use as a wide field, ultra
> bright, deep space avenger, I noticed some field curvature
> with a 25mm plossl and I can barely reach a satisfying
> focus accross the whole field of view but it frames
> M44 really well.
>
> I have since built up a telescope around the massive
> objective.  See:
>
> http://www.geocities.com/lonard3/tele1.JPG
> http://www.geocities.com/lonard3/tele2.JPG
> http://www.geocities.com/lonard3/tele3.JPG
> http://www.geocities.com/lonard3/tele4.JPG
>
> Does anyone know more about these objectives, or
> perhaps indulge me with some sort of strategy
> to abate its chromatic aberration?  I have already
> been told that one of the commercially available
> means to do this wont work for me.  Also, excluding
> exit pupil concerns, if I wanted to try my luck
> with a longer focus eyepiece, what eyepiece would
> be better at coping with the field curvature
> of a fast f/3.3?  A Nagler, panoptic, plossl...
>
> David
>
>
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