Is there a DLSR that can take black and white photos?

The DLSRs that I've seen always take a color photo then process it internally (if you've set it to take a B&W photo) from an RGB image to a black and white image.

What I'm trying to do is use the full pixel resolution of the camera's sensor to take the photo rather than the approximate 1/3 R, 1/3 G, and 1/3 B of the Bayer mosaic. This is to either do B&W photos or 3-pass color photos through Wratten RGB filters.

thx, gordon p

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My photos: http://www.gordonpritchard.blogspot.com/
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