Archived posting to the Leica Users Group, 2001/03/26

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Subject: Re: [Leica] chips
From: Dennis Painter <dwp@deltanet.com>
Date: Mon, 26 Mar 2001 20:47:04 -0800
References: <20010326200252.28840.qmail@web9503.mail.yahoo.com>

Stephen Patriquen wrote:

> The CCDs used in most digital cameras used to be made
> in 120mm wafers (they may be up to the new 300mm size
> by now).
>
> I once had a discussion about them (this is ten years
> ago, when the first Kodak/Nikon pro digital cameras
> were just out) at Kodak's TEC "country club" research
> facility outside Rochester.
>
> Almost all the production CCDs have defective "dead"
> pixels, and - sort of like cutting a diamond - Kodak
> would cut up the wafer to produce the most efficient
> mix of usable chips.
>
> However, it turns out that even back then, some of
> these wafers were perfect. That is, they produced a
> 120mm CCD - equivalent to a piece of 120mm round
> digital film. (So, theoretically, you could make a
> full-frame 120 digital back.)
>
> These chips, unfortunately, are worth about the same
> as diamonds. It was intimated that these "perfect"
> wafers were reserved for the US military, and no doubt
> ended up in a geosynchronous orbit over interesting
> parts of the world.

<snip>
or maybe in instruments like this:
http://www.cfht.hawaii.edu/Instruments/Imaging/CFH12K/

strictly available light ;-)

Dennis

In reply to: Message from Stephen Patriquen <patriquen@yahoo.com> ([Leica] chips)