Quote Originally Posted by PhotoJim View Post
Autofocus isn't the only issue. Autoexposure can be an issue too. The beam splitter is the key, as mentioned above.
But also not a clear, definite key.

For instance, the OP is using a Hasselblad. Neither the Hasselblad prisms with built-in meter nor the cameras with built-in meter require a circular polarizer. And all of those 'split' part of the light away towards the metering system.

You could indeed just 'opt' to be on the safe side, and get a circular.
But those are quite a bit more expensive than regular ones, so if you do not need one ...