Question regarding mechanical shutter vs. e-shutter

For cameras I've always checked out Jim's site to see the readout speeds of the sensor first. It can be invaluable IMO. His work even goes to the lengths of testing the crop mode of certain cameras with different readout speeds compared to when the camera is in FF. So Jim might not realise it, but it is one heck of a resource for that, so thanks Jim.

Even with slow readout speeds with bird wing movement it doesn't happen that much, very seldom in fact, but does show up now and again. It's a totally different story if the bird in flight has lets say, trees behind it, that tends to tilt the trees and on a heck of an angle at that, the same goes for fence posts etc. Wing movements are not that much of an issue, but it can raise it's head now and again, it's the backgrounds when tracking that's the main issue.

Anyway, Jim thanks for what you do with this and the testing. You might be surprised how many use it to help buy gear with 😉

Danny.

The mechanical shutter closes and then the sensor is read out. It does not matter how long this readout takes, because the sensor is no longer being exposed to light.

But with electronic shutter, the sensor must be read while it is still being exposed to light.

So A7R3 has variable slope - at least three slopes - just not variable slope in one image capture.

Please define "slope" as you're using it.

If you delve further, you will also find that mechanical shutters do not move at a constant speed; for some FF cameras, the speed of curtain roll varies about 2x over the length of travel. That opens another can of worms, the question of why exposure doesn't vary down the frame. Other variations (slit size?) seem to be cancelling out that phenomenon.

ES-mode roll, however, is quite constant.

Which is one of the reasons that EFCS gets wonky at high shutter speeds.

That's how I was thinking of it already, but there is an effective "slit" between the two independent curtains at any given time, from any given angle of incidence.