When It’s Important to Get Closer to Your Subject
Review by Fernando Santos
What if your 400mm lens can quickly become an 800mm lens, or your 800mm lens a 1600mm lens? That’s what the Canon Extender RF2x does: It doubles your lens focal range. The price to pay, apart from the $599 price tag, is the amount of light reaching your sensor: The Canon Extender RF2x cuts away two stops of light, thus an F11 lens becomes an F22.
When I tested the Canon RF2x, I found it very robust. I didn’t notice any image degradation. It was clearly made to be used with L-series lenses: the body color, the dust and water resistance, as well as the advanced optics and superior coatings, prove it (as well as the price tag). It won’t affect in any way the communication between your lens and your camera body, and lens/body image stabilization will work great.
A few things may not work as you expect, however. First, you can’t use the extender with all your lenses. As of this writing, you can only use it with six Canon RF lenses: the RF100–500mm F4.5–7.1 L IS USM, the RF100–400mm F5.6–8 IS USM, the RF600mm F11 IS STM, the RF800mm F11 IS STM, the RF400mm F2.8 L IS, and the RF600mm F4 L IS. Second, with the RF100–500mm, you can only use it between 300mm and 500mm. Third, you can’t stack extenders, e.g., stacking two RF2x to get to 4x magnification. Fourth, you can’t mount the Canon EF to RF adapter in front of the RF2x extender to use it with EF lenses. Last, but certainly not least, on all the lenses above, your focus area becomes limited to a smaller central area on your frame.
Having said all that, the Canon Extender RF2x is still an interesting add-on to have, particularly if you own the RF100–500mm lens. Despite all the limitations above, I’m keeping it in my camera bag. ■