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Old 01-03-2013, 09:51 PM
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Peter Ward
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Peter Ward is offline
 
Join Date: Dec 2007
Location: The Shire
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Quote:
Originally Posted by Shiraz View Post
That's a very good analogy, thanks Peter

Regards ray
No problemo.

The bucket analogy goes further (at one stage CCD's were nearly called BBD's, literally: Bucket Brigade Devices) .

It also gives good insight understanding the the dynamic range of various sensors.

Our two rain..( al la photon...) gauges, one made from a bucket, the other a cup, hold x-ml of water.

Let's say it was really raining and we captured 12cm of water...our cup is overflowing (saturated ...) so we really don't know how much rain fell...but our bucket still has a good deal of volume left before it fills so we can still quantify the downpour.

Not only that, but our (big pixel) bucket holds a good deal more water, so the number of millilitres (photons) we can measure, from empty to full, is in the thousands, compared to our cup which can only hold a few hundred at best.

In short big pixels give more signal and higher dynamic range... the rub is: to get good (angular) resolution, you'll also need big optics.
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