To be exact, Nikon D800/D800E, D600 and D3X use Sony Exmoor sensors using on chip converters. D3/D3S and D4 uses Nikon designed chips using external converters. Nikon D3X had both 14 bit readout (slow 2FPS) and 12 bit readout. I guess the reason Sony had 12 bit converters was more related to Bionz being a 12 bit chip. The Alpha 77 I have now has 14 bit conversion.
Pentax used Samsung chips in older cameras the K5 has an Exmoor with 14 bit readout.
DR figures from DxO (latest sensor). The DxO figures are scaled for a smallish print size. DR for actual pixels cannot exceed the channel width.
|Nikon D800||14.4||Exmoor based sensors|
|PentaxK5||14.1||Note that K5 is APS-C, impressive feat!|
|Sony Alpha 99 (SLT) ||14|
|Phase One IQ180||13.6||Best medium format CCD based camera|
|Nikon D4||13.1||Best non Exmoor design CMOS|
|Canon EOS 1Dx||11.8|
|Leica M9||11.7||Best CCD based full frame|
Updated: Small corrections + added Phase One IQ180 replacing Pentax 645D as best CCD MF camera.
We both use Sony and they have advertised on chip A/D conversion for ages.
Yes, Canon and Nikon were doing something different, maybe why they had 14 bit while we were stuck with 12. Pentax also tried high end external 22 bit converters. They went back to something basic in the next version.