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Old 04-03-2013, 11:18 PM
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Peter Ward
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Quote:
Originally Posted by Shiraz View Post
I guess we will just have to disagree Peter.

On the quantum efficiency issue, Clive's post points to an independent evaluation that compared the 694 directly with a 3200.......

If Sony had found a way to get rid of noise and not signal, they would own the telecommunications world - they don't. What they are actually doing is more likely to be something like MPP, which is discussed some way through this: http://learn.hamamatsu.com/articles/ccdsnr.html


regards Ray
Clive's post is indeed interesting...and I have to agree presents a great case for high absolute QE with the 694. Remarkable really.

MPP has been around for a while. Most CCD's including Kodak use the technique. Yet, while Sony chips are indeed cleaner looking, I suspect you really have made my case: getting rid of noise without any signal loss is probably not happening here.

The Hamamatsu link is pretty much a condensed version of my copy of Jansick's substantial tome on the subject. Both authors point to cooling as THE method to reduce dark current....which is indeed higher with larger pixels....yet while you can chill a large pixel a tad more, it's very much harder to expand small pixel to improve its well depth. On chip binning you say? Well, yes, but doesn't that defeat the purpose of those tiny pixels?
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