I know this is a lame question, but I went to two different camera stores today for a simple PC sync cord and no one knew what I needed. I have a 30d and the connection on the camera is threaded. What connection do I need for this. Also the other end is going to a Wein optical slave (model # WIWPHS ?) that has a PC sync connection. This should be simple but I've never used a sync cord before. Thanks, Randy