Shutter firing

[Indraneil]

Hi ! 
I was wondering why the shutter fires even after switching off my A7RIII. Kindly enlighten me on this  

[Chrissie]

Maybe we should first confirm, that the shutter indeed fired, after you switched off your camera.

What makes you believe, the shutter fired? Did the camera take an additional picture? Or did you possibly interpret a "sound" from the camera as a shutter firing?

Please provide more detail.

[Indraneil]

No, the camera didn’t take a picture. But the sound was undeniably of shutter firing ! And it has happened quite a few times before too, after I switch the camera off. 

[Chrissie]

So we have an "undeniable" shutter firing, as identified by you by its sound, yet no apparent picture was taken.

Let's settle for now on the undisputed observation, that a sound was emitted. The internet is full of reports from SonyAlpha users about such sound phenomena after power down, and a wide range of explanations is being given. The most detailed and plausible explanation of which (in my view) was given by this guy.

Of course you are free to believe any other explanation, which you may find when searching for the following key words:

Quote

sony alpha sound after power off

Note, how those key words focus on the observation, leaving out their interpretation.