I have bought and used the Nikon SC-28 TTL Remote Cord to take the flash off the camera, but you're limited by the length of the cable. Since my Nikon D60 will not act as a commander for the Nikon Creative Lighting System, I was looking for some other way to get some distance from my camera to the flash.
After a visit to Henry's, I picked up a Wein Hot Shoe Slave. It has a slave sensor and is supposed to fire the flash when it detects another flash (in my case, the on-camera flash set to low power). Well, that's the theory. The damn thing didn't work. It would fire an old (60s era) Sunpak from the PC cord, but nothing would fire from the hot shoe. Thinking it was perhaps a bum unit, back to Henry's I went. We tried another Wein unit but with no luck at all. We tried a "peanut" slave unit and a PC to hot shoe converter, but also no luck. The things generally look like a piece of junk and seem to perform that way as well. Thinking that was the end of the line until I get a Nikon D90 (which can control my Nikon SB-600 flash remotely), the sales guy mentioned he had a Nikon SU-4 Wireless Slave Flash Controller in their used gear section. We tried it and it worked. It worked well. And was less expensive than the silly Wein hot shoe slave.
I've had it for just over a week now and I'm pretty happy with it. It's hard to find out a lot of info about them on the internet, since they've generally been used with pre-digital flashes. Most hits in a Google search or a Flickr search lead to discussions of the Nikon SB-800's "SU-4 Mode", which fires that high-end flash as though it's on an SU-4 unit.
So to help anyone who is looking for info on this unit, here is what I've found out:
- It is not a dumb slave, in that it just sends a fire signal to the slaved flash when it sees another flash. On Auto mode, it tells the slave flash when to start firing and when to stop. If you put the included diffuser over your built-in flash, it does a reasonable facsimile of TTL.
- In Manual mode, it will just send the fire signal so you can use full manual controls on the slaved flash. I expect you can use this as a slave for any other brand of flash.
- It is very small and easy to lug around. The feel of the thing is pretty solid.
- It is very adjustable: since you need to have the sensor point in the direction of the master flash, the hot shoe rotates and the sensor rotates.