Electronic shutter: advantages and disadvantages

assaft wrote:

Jacques Cornell wrote:

assaft wrote:

Henry Richardson wrote:

I discovered today that Auto ISO is broken when using the electronic shutter. I am using A mode.

electronic shutter: @ 150mm - ISO 200, 1/30 f5.6

mechanical shutter: @ 150mm - ISO 2000, 1/250 f5.6

I have been using Auto ISO a lot since I got the E-M5 in 2012. Use it on the E-M5, E-M10, and E-M10II. But, now with the electronic shutter there is a bug. With all the 3 cameras using the mechanical shutter, Auto ISO tries to maintain a minimum shutter speed of about 1 / focal length * 2 and will raise the ISO if it has to. With the electronic shutter though it is allowing the shutter speed to go way too slow while keeping the ISO very low. I switched back and forth between the electronic shutter and the mechanical shutter and could see the shutter speed and ISO keep changing every time I switched.

I have really been liking the electronic shutter in the last few days so I am very disappointed to find this big bug in a feature I use a lot.

Yes, and it was reported also regarding the E-M5 ii, see here. There's an hypothesis that it makes no difference that the shutter speed is so slow because the slow read out is the limiting factor. Actually I'm not so sure about that, but just to let you know.

That's a bad hypothesis, because slow readout is not the same as slow shutter. Slow shutter with a stationary subject can result in motion blur in a handheld shot. E-shutter with slow readout but a fast shutter speed in the same situation causes no problem at all (unless the shooter is bouncing on a trampoline).

Maybe I got something wrong so please correct me. If we assume that the readout takes 1/25th I take it that the camera needs 1/25th to read the data from all photo sites. So even if the shutter speed is 1/8000th and due to that every photosite is exposed only for 1/8000th, it will still take the long 1/25th to traverse from the first site to the last one. So handshake during these 1/25th can still ruin the picture because it changes what falls into the photosites that are being read last. It follows that when using the E shutter, the shutter speed only controls the exposure and doesn't really help to combat handshake or subject movement. In a way, it doesn't matter if it is the subject or the hand of the photographer that moved during the 1/25th readout, both movements affect what's recorded in the photosites and may degrade the picture. Am I wrong?

I would say half right.  The whole refresh is true but you still can get the fast exposure you are dialing. But you get a rolling shutter effect if there's camera shake.  As for subjects moving really fast you could get a rolling shutter effect but normally it ends to freeze them as you would expect.