Cheap flash trigger will help Canon users focus in the dark

There's a new budget flash trigger called the Wansen RF-602. It has a built-in laser AF-assist lamp.

Wansen RF-602

There’s a new budget flash trigger in town. It’s called the Wansen RF-602 and has a built-in laser to help you autofocus. So what?

Many cameras have “AF-assist lamps”, a little bulb that – when you press the shutter button halfway – shines light on your subject to help the lens lock focus. Canon cameras don’t have this feature, which means that in the dark, even the latest EOS 5D Mark III can’t autofocus without external lighting, such as a handheld torch. The Nikon D800 has no such trouble, as this video demonstrates.

It’s easy to overcome this problem by putting a speedlight on the hotshoe. Most decent flashguns have their own infrared AF-assist lamp to help you out. There’s even a setting (in Canon Speedlites) to have the AF light on with the flash tube switched off:

AF assist beam without flash in Canon DSLR camera menu settings
How to use a Canon Speedlite for AF assist without it flashing

But Speedlites tend to be big, heavy and expensive. They also get in the way of using radio triggers, for the enlightened off-camera flash users amongst us. Is the extra bulk necessary? The Pixel King and Yongnuo YN-622 have AF assist lamps but are quite expensive if that’s all you’re getting them for.

The Wansen RF-602 is supposedly a solution to this problem. It’s a budget flash trigger that looks and sounds like a Yongnuo RF-602 (and is even compatible with it, according to some sellers). On the front of the transmitter there is an AF-assist lamp that emits a red laser beam when you autofocus.

Wansen RF-602

There are a couple of other improvements over the Yongnuo RF-602. You can now turn the transmitter off so that it doesn’t run down the battery in your bag, plus you can switch off the laser if you find it distracting. Both transmitter (RF-602TX) and receiver (RF-602RX) have locking wheels to keep them mounted more securely. The Wansen sync port is a standard 3.5mm jack, not the obscure proprietary socket seen on the Yongnuo version.

Wansen RF-602TX transmitter


As a bit of an unknown brand, the Wansens will need some early adopters to try them out before we know if they’re worth buying. Does the laser beam help you autofocus, as advertised, or will it blind your models? Is it really compatible with the Yongnuo RF-602? Fortunately, it doesn’t cost much to find out: the Wansen RF-602 is on sale now for under $30 a set. Click here for listings.

David Selby
David is a keen photographer and has been editor of Lighting Rumours since 2010. When not writing about lighting, he works as a data scientist at the University of Manchester, UK.