I have a Bronical SQ Ai on which the metereted prism (an AE prism S) is indicating and exposing way off. Bright sunny day with 100 iso film was giving f2.8 at 1/30 second with 100 ISO film. That should be around f16 at 100th under those conditions.

The Ai uses a film speed setting dial on the film back with numerous connections to get the informatin on film speed back to the finder.

I checked the resistance of the setting circuit at various ISO values on the terminals at the top of the film back and they are varying with ISO setting from around 380 ohms at iso 100 to above 1.5 kohms at 6400 iso so this appears to be working.

Can anyone direct me to a technical or repair manual for this camera so I can check the operation of the entire system and pinpoint the fault, which at the moment I suspect to be the meter itself.

New batteries make no difference to the problem.