In a recent interview Sony’s head of marketing in Russia Andrey Kurganov provided some hints at why the a7s III mirrorless camera is still not released:
Sony had trouble keeping up with the demand for the Sony a7III globally
They were surprised by the demand
The Sony a7III is their best selling camera
It’s Andrey Kurganov’s opinion that we are still waiting for the Sony a7SIII because all of the technology needed isn’t ready yet.
The a7SIII can improve resolution and video detail, but they can further develop 4k or go to the next level
To do 8k the a7SIII will require very fast storage that isn’t available today
If you’re shooting in the rain with an a7III you should keep hot shoe closed because water can get in the camera with it off.
The a7III is better sealed on the top than the bottom
The a7III isn’t better sealed because the camera would become too big
If they can make the moisture protection better in the future they will
Sony probably won’t add deep color to their a7 line because they have the FS7 and FS7II for that
Sony won’t add features just for marketing if they add something it is fully featured
The a6400 is a step up from the a6300 so it doesn’t have IBIS an APS-C camera with IBIS has to take a step up in price and class like an a6500 replacement.
Not everyone needs stabilization and the a6500 isn’t a successor to the a6300
The FDR-X3000 hasn’t been replaced yet because it is still competitive and the RX0II can also be used as an action camera, but it’s not a replacement
Blogging is way bigger than the action camera market
Sony doesn’t do incremental upgrades just to add generations
Action cameras require a different lens than vlogging cameras