black/white DSLR's how do they work

Discuss older Nikon-based Kodak digital SLRs, including DCS 100, DCS 200, NC2000, DCS 400/600/700-series, etc. Ask questions, post general comments, anecdotes, reviews and user tips.
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Wolfi
Posts: 37
Joined: Wed Nov 09, 2005 8:33 am
Location: german living in south France

black/white DSLR's how do they work

Post by Wolfi » Sun Nov 13, 2005 3:27 pm

Hi,

I would love to own a 760m but it's out of reach for me. How do these bw cameras work? I've heard about a Bayer mask which is taken off. Is this a physical mask, are bw sensors different from coulour sensors, can sensors be swapped.

How did the three shot cameras work, and do these give more resolution for the same chip than one shot colour Bayer

thanks

Wolfi

Stan Disbrow
Posts: 579
Joined: Fri May 20, 2005 7:33 pm
Location: Raleigh, NC USA

Post by Stan Disbrow » Mon Nov 14, 2005 3:47 pm

hi,

Well, the mono units work the same as the color. The only difference is in the fact that there is no color filter array on the imager. That means that there is only luminance information in the data, so the post-processing has to be done a little differently.

Instead of performing the de-mosaic step, where the software calculates the value for the other two colors at each pixel, it has so skip that step and make all three color values equal to that which is present.

What you gain, in the end, is a higher dynamic range as well as higher sensitivity (the color filters subtract light energy as the price to be paid for seeing in color) and also signal-to-noise ratio. In other words the images from a mono DSLR look more like B&W film images, which is the whole point, actually. ;)

What you lose, is color, of course. You can make that back up by using a color wheel in front of the lens. You then take three shots, one with a red filter, one with a green filter, and one with a blue filter. You then merge the three 'monochrome' shots in post processing to produce a color image. Of course, this can only be done for those shots where nothing moves. :p

later!

Stan
Amateur Photographer
Professional Electronics Development Engineer

Wolfi
Posts: 37
Joined: Wed Nov 09, 2005 8:33 am
Location: german living in south France

Post by Wolfi » Sun Nov 20, 2005 11:22 am

Thanks Stan,

Yes, the point is to make great looking bw shots, which the camera did before a bad microdrive messed up the camera. It does not recognize any other cards any more. Perfhaps can I repair it by loading news firmware via the scsi port....

What are the 4 shot cameras? I understand the rgb filtering wheel, is there something like shadow exposure with the three (or no) filter?

Thanks

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