"Alfred Molon" <(E-Mail Removed)> wrote:
> In article <(E-Mail Removed) .com>,
> says...
>
>> Eh. I'd never buy a four-thirds camera. Those sensors are just way too
>> small. 1/4 the size of a 35mm frame means 4 times the noise.
>
> Nonsense. Maybe two times, but not four times.
I agree. You are exactly right.
To achieve the same photon shot noise levels, a sensor 1/4 the area must use
an exposure four times longer.
Thus the larger camera seems to be four times more sensitive. ISO 800 here
looks like what the 4/3 users see at ISO 200.
But noise goes down as the square root of the measurement, so the amplitude
of the 4/3 camera noise is only twice that of the FF camera.
So, as you point out, the smaller camera is only twice as bad.
So while a photographer would find the 4/3 camera to have "four times the
noise", we theoreticians realize that it's only twice the noise.
David J. Littleboy
(E-Mail Removed)
Tokyo, Japan