As I understand it, the flash synch is limited to whatever your camera can handle. If you're using an RB-67, your lens's fastest should be good, but use it with a focal plane curtain shutter, and you're likely to be limited to 1/30-1/250.
Originally Posted by mweintraub
I've had great luck with the ones like I listed previously. Several folks make them, and they're cheap enough on Amazon. You can even get a set with 1 TX and 3 RX. They work with PC synch cables, so they're not brand specific.
I do, however, like the Cactus ones you listed as a possible upgrade for my digital work. I'm planning on getting the 568EX2, so they might be worth an extended look! Thanks for the link!