After returning from yet another fantastic photo tour in Alaska’s Arctic–which always produces interesting photo opportunities–I am reviewing a few test shots with Canon’s 200-400 f/4. I’ve been curious how the lens will perform using both the built in 1.4x and then adding another external 1.4x. This shot was taken while a very friendly red fox allowed a close approach. I’m not suggesting that two 1.4x converters is an optical preference, but I had to try it out. The photo is amazingly sharp considering that it was taken with 2 converters. It will handle a two page spread beautifully. The depth of field however is pretty narrow when shooting nearly 800mm at 25 feet. And the execution of this must be done well. On a stationary object, it was not a problem. Auto focus is restricted to the center point only at f/8 on this lens, so it’s use will be in specific circumstances. However, it is good to know that the lens can pull this off when in a pinch.