words and image source/photographer : Eksovichea Tito Hak

The RF-603C usually comes as a pair. The reason being that one is usually mounted on the hot-shoe mount of your Canon DSLR and acts as the master radio wireless flash trigger, and the other will act as the receiver whilst usually having a flashgun mounted on it that doesn't have radio wireless flash capabilities, which basically completes your simple off camera radio wireless flashgun trigger setup. You can also buy additional RF-603C units to add further additional wireless remote flash guns in a multi-flashgun setup. The 'C' part of the name indicates that its for Canon DSLR's. 

In addition to this the RF-603C can be used to remotely trigger the shutter release on your Canon dslr camera. This is done by mounting one of the RF-603C units on the camera and using the other one (without a flash mounted on it) to set it off by pressing the button on it. However, the one that's mounted on the camera requires a PC sync cable to be connected from the RF-603C to the camera body. This cable is usually supplied with a twin pack kit. Be warned though, although it's for canon there are two different kinds of PC sync cables for the Canon DSLR's. For example the PC sync cable needed for the 60D is different from the cable needed for the 5D despite both being Canon DSLR's. Make sure you select the right one before buying.

In addition to that, if you already have a YN-560III flashgun with built in wireless radio slave flash capabilities, you can also use the RF-603C to trigger that as part of your multi-flashgun setup.  There's also a Nikon version too. 

There's not much talk of these in professional circles, since it doesn't come anywhere near to the kinds of usefulness you can get out of something like a pocket wizard which offers far more advanced flash control features at a much higher premium. But for simple flash triggering this does the job more than adequately. Which brings us to the next part, reliability, and thus far its proven to be very reliable for operating within the scope of its limitations. The range is said to be 100m, but generally I've only really used it at about 25mm so far. All in all good performance for the price if you just want simple basic radio wireless multi-flashgun triggering. (ie. there's no ETTL or TTL).

Other stuff about it...

- It runs on 2 triple A batteries.
- has 16 different radio frequency channels which it can be set to.
- 2.4Ghz capable.
- I tested it with a Sony NEX camera via an adaptor. It don't work.