Using TTL on Bronica SQ-Ai?

I am about to throw money into making my Bronica SQ-Ai do TTL flash work. I'll probably be getting a Metz SCA flash plus the 386 adaptor. Or the Sunpak.

My question is: will I need to buy one of those metered prisms, either the AE or Manual, in order for the TTL to work? Or can I stick with the waistlevel finder or unmetered prism I am currently using?

The Bronica TTL flash control is totally disconnected from, and does not at all depend upon, the metering prism.

The fact that the SCA386 is not connected to the metering prism means that Bronica will let you use Auto for ambient exposure control via the metering prism, while the SCA386 allows independent control of the flash exposure simply by dialing in a different ISO value into the metering prism. For example ISO 160 on the metering prism with ISO 320 on the SCA386 permits automated exposure control for ambient while the flash is automatically set at -1EV flash fill.

If the TTL flash control does not depend on the metering prism, then why do the metered prisms advertise TTL? (http://www.tamron.com/bronica/prod/sq_vfind.asp) This would be one of those occasions where I have slight regrets in buying into a discontinued system for the sake of saving $$$ - documentation is so hard to find. Well fortunately, there's APUG.

Basically, in any indoor situation, I want to pick a shutter speed, an aperture (obviously I'll be several stops under), and let the flash expose the scene predictably and consistently. Or, is Metz Auto mode really good? My own experiences with Auto mode (Vivitar flash on a Nikon Manual focus) were unreliable and I always had to bracket.

applesanity said:

If the TTL flash control does not depend on the metering prism, then why do the metered prisms advertise TTL?

Click to expand...

Because they meter Through The Lens.

well of course that make sense. I feel dumb.

Metz in Auto mode is terrific. Metz under Bronica flash TTL exposure control is even more terrificker because it sees only what the lens sees!