| Lee Ying |
October 27th, 2010 08:42 PM |
Quote:
Originally Posted by Perrone Ford
(Post 1582813)
Lee,
Would you mind explaining how the 5D, with the same codec, the same 4:2:0 color structure, and a lower bit rate (40Mbps vs the 7D's 48Mbps) gives the 5D superior color dynamic?
And would you also define what "giant screen" means? I've watched 5D and 7D footage on my local 28 and 42 foot screens and frankly they both look essentially identical to me. I'll admit that I have not seen either on the IMAX screen next door, so maybe that is what you mean by giant.
I can certainly agree that the 5D is the superior camera when shooting without adequate light.
|
yes, they have the same 4:2:0 color structure, but the strength of the signals that go into producing the grayscales (which produce the colors) are quite different. With 2.5 times area per pixel on 5D as 7D, the signals from 5D will be 2.5 times that of 7D per pixel. Stronger signals mean higher signal to noise ratio and greater dynamic range.
Now, the difference may not be dramatic in area where signals from both cams are way above the noise floor, but most scenes will have some dark areas in the frame. You can crush the blacks to get rid of those dancing noise in the dark area, but you lose some grayscale, and thus color dynamic range. So at least in theory, 5D will be superior in those regards. I think most people will be able to appreciate the difference in low light scenes, such as those indoors, taken by the two cams.
When I said "giant screen" I meant viewing my own works on the big projection screen, and I can see those inadequacies from a crop sensor. I imagine the works we see in commercial theaters were filmed in controled lighting situations where the difference of the sensors is not easily noticeable. |
