I just picked up a Sinar Automatic Aperture Shutter off of Ebay and it looks to be in brand new condition. I'm having some issues figuring it out though and was wondering if anyone had any experience with these? There are two available plug ins for plungers. The one on the side appears to be an aperture preview and the one on the bottom cocks/closes the shutter. Is this correct? How does one sync these to actually fire the lens?