Re: [ATM] Schmit corrector grinding

["matt" <electro_optic@bellsouth.net>]

I accidentally came across a very interesting alternative to a custom field
flattener for a curved focal  plane scope a couple of years ago .
It is a coherent fiberoptic faceplate.
It has one flat side and the other side is concave , with the radius of
curvature of the focal plane.
The curved side does not require optical accuracy polishing. It doesn't need
to be within fractions of a wavelength but jus to fractions of a millimeter
of the desired curve ! It does require to be smooth though in order not to
scatter.
The ones I found are made of around 10 million optical fibers bundled
together . Measured fiber diameter is under 9 microns , total device
diameter is 36mm .
I have no idea of their original cost but they're available from Surplus
shed for $5 each .

http://www.surplusshed.com/pages/item/l3172.html

These might make a great distortion and aberration free field flattener .

best regards,
Matt Todor





----- Original Message -----
From: "Dominic-Luc Webb" <dlwebb@canit.se>
To: <tillerman1@videotron.ca>
Cc: "ATM Superheros" <atm@atmlist.net>
Sent: Tuesday, February 13, 2007 1:18 PM
Subject: Re: [ATM] Schmit corrector grinding


>
> I would be interested in your sources of info on this topic,
> if this is possible. I enjoy reading on this subject and
> once in a while find people have used sources I was not
> aware of.
>
> 500 grit sound close to what I use. The curve on these
> correctors is usually very small. Consider one of my
> Schmidt designs using rather strong curve (primary is
> 310 mm F/1.55):
>
> http://www.canit.se/~dlwebb/catadioptric/310schmidt/schcorr.jpg
>
> You will notice the deepest point in the corrector is only 80
> microns less than the highest point (axis). Design uses 6 mm
> glass, which is readily available where I am and design can
> tolerate a little less thickness. I went for 600 grit assuming
> this would get me my curve quickly without removing excessive
> glass.
>
> Is the other side of your corrector flat or are you splitting
> the curve between the two sides?
>
> Dominic-Luc Webb
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>

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