« on: February 28, 2014, 05:23:42 AM »
Seeing as the D4s is coming with a 'new' 16 mp sensor, I'm going to be brave and guess the 7DII will also be 16 mp, aps class leading low light performance, very fast and no pop up flash. See you in the second quarter.Please God hear our prayers. Only 16 megapixel camera with ISO 3200 without noise bothering, costing less than $ 2000.
I'd rather have 24, 32 or even 72MP. More resolution and less noise that way.
That's a misconception. If you account for noise as a factor of total sensor area, it doesn't really matter how large or small your pixel are. The expectation is that you are downsampling any and all of those sensors to some common output size...i.e. the same magnification.
Otherwise, smaller pixels are always going to have more noise at the pixel level. Any technology you might apply to smaller pixels is applicable to larger pixels. Any potential technological gains you might have that allow smaller pixels are only going to make bigger pixels better. In no way can smaller pixels be less noisy than larger pixels. They may resolve more detail, but assuming Q.E. remains roughly the same, that detail WILL be noisier.
All else being equal, if you have 6 micron pixels and 3 micron pixels, the 3 micron pixels are going to have 1/4 the FWC. A 6 micron pixel might have 60,000e- max charge at ISO 100, where as a 3 micron pixel is going to have 15,000e- max charge. Since noise is the square root of the signal, you have 244e- noise with 6 micron pixels, and 122e- noise with 3 micron pixels. In other words, you have a 244:1 SNR with 6 micron pixels, and a 122:1 SNR with 3 micron pixels.
The only way to make those smaller pixels equal to the larger pixels is to downsample by a factor of two.
What's the problem with having a high resolution sensor that allows detailed images at low ISO and then downsampling to reduce noise when you need to used higher ISOs?
I'm asking because you seem to know your stuff and I'd like to get this cleared up once and for all!