Bronica SQ Metering Prism Query

I just bought a simple ME metering prism finder S for my Bronica SQ-A at auction.

Whenever I point it at something and press the silver button on the side for a reading, I get a red light, indicating underexposure. I have set it at various exposures down to 1 sec at f2.8 but even when I point straight at a 100w light, I am still getting an indication of underexposure.

How does the meter know what film speed to work with? I dialled in 400asa on the film back, but can the meter pick up this info? Is that the right thing to do?

It could need calibrating. Does anyone have experience of using these meters?

I have both the ME and the AE prisms. I use them on the SQ-A & SQ-AM.

Are you using the shutter speed dial on the camera body or the one on the side of the ME prism? The dial on the side of the body has no effect when this prism is attached.

Yes the dial on the back is where you set the ISO. Notice the back has 2 contacts on top that mate with the finder.

If you had the AE prism and set it to manual mode; then, the shutter speed dial on the body would change the speeds.

Both the ME & AE seem to handle contrasty scenes well while biasing a little toward overexposure - but with print film this brings out the shadows. With transparancies I would start with 1/2 to a full stop underexposed.

http://smg.photobucket.com/albums/v57/Jim.e/?action=view&current=39530009.jpg

Bronica Prism discoveries...

jime11 said:

Both the ME & AE seem to handle contrasty scenes well while biasing a little toward overexposure - but with print film this brings out the shadows. With transparancies I would start with 1/2 to a full stop underexposed.

http://smg.photobucket.com/albums/v57/Jim.e/?action=view&current=39530009.jpg

Click to expand...

Thanks for the time taken to reply you guys.
The Prism is a bit of a mystery.
I discovered that the silver button in the middle of the dial is the trigger for the reading, something that was not clear before. I dialled in the film speed on the back, and noticed the contacts. So far I still only have a red light, no green light, so maybe it needs calibrating, if that is possible?

Or the voltage on the batteries is low.

Steve