Mirrorless Cameras EVF Lag and Blackout

As a long term mirrorless user on micro four third I have always ignored the EVF blackout that you get when you shoot with the mechanical shutter on underwater

This is due to the fact that most high profile MFT cameras run the EVF at 60/120 fps so your black out is the total of the shutter time plus readout time. Readout time in MFT cameras is currently 60fps so it takes 16ms + any additional lag of the EVF/LCD to go back to real time. In general this is around 30-40ms so quite ok and you can up the EVF refresh rate if that bugs you. This reduces the lag but has no effect on the readout as that is fixed.

With the Sony A1 the readout is 200 fps and as it has a stacked sensor if I shoot with electronic shutter I don't have any blackout. I am therefore investing in a trigger that allows to shoot with electronic shutter.

One tip that I can give to DSLR users that are going into mirrorless is to evaluate carefully the readout rate of the camera they choose as on a non stacked sensor (majority of full frame are back or front illuminated but not stacked) as this influences the duration of the black out

To give a reference a camera like the A7R4/5 but even the A7III/A7IV have readout of 15-19 fps. This means your EVF black out will last around 100ms which is 1/10 of a second

This is not  bothersome to many but as a DSRL user with an optical viewfinder and no blackout this can be bothersome. Obviously you still have to wait for the camera to readout before you can shoot but the optical viewfinder provides uninterrupted view.

Some new mirrorless users struggle significantly with EVF blackout and while camera specs are quite clear about the EVF refresh rate readout rates are not published. A good tip is to look for maximum burst rate in electronic shutter as that is normally limited by the readout not by the buffer. Signs that a camera is a slow reader include not being able to output 4k video at 50/60 fps using the entire frame. This indicates the readout is slower than those. Today very few full frame cameras have this level of speed

I thought this could be useful to many DSLR users migrating in the near future