dugaut wrote:
Wouldn't we divide by 1.5 squared for area since it's reading the sensor area? I thought I saw readout speeds for shooting in crop factor or one of the video modes that doesn't sample the whole sensor that were single digit. Jared Polin, Jan Wegener, and another technical youtuber among others talked about this.
Steve Spencer wrote
duncangr wrote
speedmaster20d wrote
For those interested I just measured the readout speed for the A7R6 (as well as A7R5 and A1 II that I have at hand). I had preordered the camera and it came yesterday.
I used a pulse generator driving a high speed LED to generate a precisie optical waveform and capture it with each camera (will put more details on my channel)
summary
--------------------
A1 II : 3.9 msec
A7R5 : 94.35 msec
A7R6 : 19.7 msec for RAW (Lossless compressed or compressed HQ) / 14.1 msec for lossy compressed
it is quite a bit behind A1 series
one pleasant surprise : In A7R6 the EVF resolution does NOT drop like all other Sony cameras when you engage the continuous AF by half-pressing the shutter. It remains high and the EVF brightness is great as well BTW thanks, you didn't happen to test in APS-C mode did you. Hopefully Arash can give us an actual measurement, but it should be basically a function of the crop factor so something close to 13.1 msec (i.e., 19.7 / 1.5) in RAW or lossless compressed or compressed HQ and 9.4 msec (i.e., 14.1 / 1.5) in lossy compressed.
As snapsy described you only gain speed by reading less rows and you don't gain by reading shorter rows, so the sensor scan speed should just be divided by 1.5, and that does get you just into single digits for sensor scan speed if you use both APS-C and lossy compression. Perhaps the single digit numbers you saw were both APS-C and lossy compression.