Everyone who has ever taken pictures in dim light will know what a bugbear it can be for a camera to autofocus in the dark. Before long, the lens starts “hunting” throughout its focus range, trying and failing to lock on to the subject.
Many external flash units have built-in AF-assist lamps — little LEDs that throw just enough light onto the subject for the lens to focus successfully. Nikon also integrates AF-Assist Illuminators into its DSLR cameras, as do some other manufacturers including Sony.
But Canon does not, leaving its photographers with the dilemma of whether to mount an otherwise-redundant Speedlite just to get AF-assist functionality.
Help is at hand. Yongnuo, the Chinese photo accessory manufacturer, has brought out the YN12AF AF-assistant, a dedicated autofocus illuminator for Canon cameras. This little module will light subjects up to 12 metres away when the shutter button is pressed halfway, helping the camera to lock focus in low ambient light.
The YN12AF has a low profile and charges from USB, so the photographer avoids the bulk and weight associated with a full-sized Speedlite loaded with AAs. It is even possible to turn off the AF-assistant via Canon’s Custom Function menus.
There is no word on pricing or a release date, but with any luck these things should be less than $20. Check the official Yongnuo Store for availability.