duncangr wrote: speedmaster20d wrote: Fred Miranda wrote: 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
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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.
This seems right to me, and getting around ~9 ms in APS-C (lossy compressed) actually makes it a very usable option for action shooting. I don't remember exactly, but I think the original A9, the one that made a lot of action photographers switch over pretty quickly, was around 5-6 ms.
unfortunately that does not help. it is the scan slope (time to read a single row) that matters not the total readout time. The distortion is a function of panning speed relative to the scan slope. I checked and the slope does not change in APS-C crop. the distortion will look identical i.e. it will look same as just cropping the FF image in post.
I agree the ciritcal readout time (beyond which is almost don't care) appears to be about 5-6 msec for a FF sensor (or 3-4 msec for APS-C).... so the A7R6 falls short by 2.5X in best case scenario
the issue I take is the strong emphasis Sony has put on "ready for pro action" for this camera... not true advertising IMO. Otherwise it's fine for what it is.
But if you have the same FOV in APS-C mode as in FF mode then the slope will be quite a bit less. As you rightly point out cropping alone will make no difference.
the slope does not change in APS-C mode, it's the same. Slope is limited by sensor electronics not FoV or anything like that.
if you want to get same FoV in APS-C as FF you have to walk quite a bit back from the bird that will reduce the rotational speed as you pan from much farther away and makes the distortion less .... but no one on earth would switch to APS-C and the walk back from the bird to end up with a low resolution image of a far bird.... makes no sense
