View Single Post
Old 05-03-2013, 09:26 AM
Registered User

rally is offline
Join Date: Sep 2007
Location: Australia
Posts: 896
I wonder if we are missing the fact that the Dynamic Range of the chip whilst important its only just one parameter of the many needed.

I'll give an example
For the argument lets take a hypothetical (extreme) example of a Skipper Chip that is 'available' to amateurs to illustrate the issue.
This hypothetical chip has the advantage of extreme low read noise per the published Skipper CCD design potential of 0.2e-
These chips have actually been built !

Its Dynamic Range is therefore 88db or 25,000 using the standard calculation

If we compare that to a few cameras we know and use . . .
STL11000m - 73db or 4545
Sony ICX294 - 77db or 4000
DSIPro ICX254 - 67db or 2261
KAF8300 (std) - 70db or 3188
ST10 KAF3200 - 79db or 8750

Then on first inspection 88db looks extremely impressive doesnt it.
Well ahead of the pack

But if I then reveal that the well depth in this hypothetical example is only 5000e- what would we say ?

The reality is that it probably wouldn't be much good for our purposes
Yet 5000 is actually 12.3 bits, so in theory it ought to be quite useful.

When Sony release a 15mp, 9um chip then we'll have something !

Reply With Quote