Hi, I'm new to this site and photography so I apoligize if I sound like a total idiot. I got a Sigma SA-7 film camera a couple months ago. It has a bulb setting but no cable release. I couldn't figure out a way how to use it. I was under thhe impression that to take a picture in B mode, I'd have to use a cable release to prevent camera shake that could occur if I just kept pressing the shutter release. What should I do? Thank you for your time & info..