Notification: message ignored

[P3D Bob Wier <wier@xxxxxxxxxxxxxxx>]

We are having a little trouble with John's address - here is a message
he sent...

--BW


>>From johrt@xxxxxxx  Mon Mar 10 23:27:00 1997
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>       id sma5HACzR; Tue Mar 11 05:27:12 1997
>Message-Id: <3324DE93.617D@xxxxxxx>
>Date: Mon, 10 Mar 1997 23:24:51 -0500
>From: P3D John Ohrt  <johrt@xxxxxxx>
>Reply-To: johrt@xxxxxxx
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>To: photo-3d@xxxxxxxxxxxxxxx
>Subject: Re: Broken Pentax Beam Splitter
>References: <3328c78f.88535577@xxxxxxxxxxxxxxx>
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>
>P3D, Eric, J, Fleischer@xxxxxxxxxxxxxxx, MD wrote:
>> 
>> A few days ago, I had a most unfortunate accident. I dropped my camera
>> bag, with my camera and Pentax beam splitter in it. It must have
>> landed exactly wrong, because one of the front-surface mirrors
>> shattered. The case of the splitter isn't bent or dented in the least.
>> 
>> The broken mirror is 1.5" x 1.75" x 3/32".=20
>> 
>> Does anyone know where I can get a replacement for this mirror, and
>> how to get the mirror mounted in the splitter?  It is not apparent how
>> to open the case, and I don't want to damage it trying.
>> 
>> Edmund Scientific has some front surface mirrors, but they are not
>> quite the right size. They are too big, and I suspect it would be
>> difficult to cut a mirror down without damaging it.
>
>If the broken mirror didn't have the edges protected by flat black
>paint, then the odds are that the precise size is a little flexible
>because a baffle is likely protecting the edges from stray light.
>
>Making an optically flat mirror is no big deal,  amateur telescope
>makers consider it about the eaasiest of their tasks.  Question Edmund
>about their surface flatness. From what I have heard of Nikon, their
>spec is likely 1/40 lambda (lambda = wavelength).  You don't much care,
>but it will likely be quoted about lambda = 635 nm.
>
>Mounting and adjusting the mirror is more tricky and I would suspect you
>need access to an optical bench to do it quickly, but trial and error
>will do it.
>
>I would ask Nikon for a repair quote.  If they say forget it and buy a
>new one, well you could do that or you could play around given your
>time, patience and aptitude.
>
>If you can wait a bit, I will ask an acquaintance, a professional
>telescope and astrograph maker what he thinks.  He also has some pretty
>pricey cameras :-).
>
>I will post the answer.
>
>
>  



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