Quote Originally Posted by hoffy View Post
I have to admit that this is an interesting conversation and something that I have been considering. I want to possibly under expose the ambient in the examples that I have been considering.

Would a Thyristor type flash work OK for the fill light? Or would the abundance of ambient light fool the sensor?

Cheers
Thyristor type flash units (assuming a modern unit with a sensor) work fine but their sensors face the same challenges any reflective meter faces.

That can be mitigated with "barn doors" or some other form of shading device used to exclude the background from the sensors view. That's not always needed or beneficial. Many, if not most times, simply pointing the front of the unit at the subject is enough.

The other wild card is the camera in play. Reasonably modern TTL metered cameras (like a Nikon N90s or F4) with fairly modern lights (say an SB50 which lacks its own sensor) that can talk to the camera and get instructions from the camera on how to fill as the shutter button is pushed.