A Second First Look at Canon’s EF 1.4x II

At this point, I’ve taken the EF 1.4x II into the field twice now, so this is my thoughts regarding the converter after a having used it in the field with a EF 100-400 f/4.5-5.6L IS USM on a EOS 40D as well as some very brief testing on an EOS 50D at least using contrast detection AF in live view mode.

First off a comment about caps. The front cap is is different from a camera body cap, it’s deeper to allow for the converter’s protruding front element. The converter’s front cap fits on a body fine, but converse doesn’t work at all. I only mention this because if you drop all your caps in a pocket in your bag you’ll can’t readily tell them apart by feel.  Now this hasn’t been an issue for me, mostly because I make sure to drop my TC caps into a different pouch than the rest of my caps.

Focusing, more specifically manual focusing, or at least that’s what I’m limited to. Most of Canon’s EOS bodies disable the auto focus system when the lens or lens and converter combination has a maximum aperture slower f/5.6. EOS 1 series bodies get a little more leeway, with the center point being sensitive to  f/8. That means when paired with either the EF 100-400mm f/4.5-5.6L IS USM, EF 400mm f/5.6L USM or EF 800mm f/5.6L IS USM, only EOS 1 series bodies will have autofocus.

There is a widely used “tape trick” out there, that prevents the teleconverter from reporting to the camera. This way the camera doesn’t know the aperture is f/8 and it doesn’t disable the AF system. While this sounds good in theory; in practice, at least with the 100-400 and a 40D, the results were far form usable for me. AF hunted for all but the most simplistic scenes, further even when it locked on it was frequently front or back focused by a good margin.

Given my testing, this isn’t a time where I think Canon was just being conservative, it really is slow enough and inaccurate enough that it’s best to not even try and use it. Actually I think it speaks volumes for how poor the performance is was when you consider that I’d rather focus manually.

Surprisingly, the contrast detection used by the 50D in Live View mode (and I suspect the Rebel XSi, but I haven’t tested that so I can’t be sure) does function with the lens and TC combination. This gives the 50D an edge if you’re looking for an inexpensive body to pair with a slower than f/4 lens and still use the EF 1.4x II with it. This configuration isn’t fast by any means, however. It took 2 to 3 seconds to lock focus on a brightly lit subject, so you won’t be tracking moving subjects, let alone quickly moving ones.

Also there are performance differences between the EF 100-400mm f/4.5-5.6L and the EF 400mm f/5.6L. The 400mm f/5.6 prime focuses faster and is reported to work better with the “tape trick” across the board. Unfortunately I don’t have one, so I can’t test the validity of this.

In the mean time, with the tape trick being less than stellar, and the lack of auto focus I’ve been working on learning how to judge focus manually though the viewfinder. My technique right now is to use the viewfinder to get initial focus, then flipping on live view and checking that I’m focused where I want to be. Then with live view off, I take the picture. I don’t use live view for shooting as I’ve found that with live view enabled the metering can be off, sometimes close to a stop over exposed.

The more I use the TC the more comfortable I’m getting with doing everything through the viewfinder. But the risk of loosing the shot with out checking focus in live view is still there. I found that out the hard way last Sunday when I was shooting a Red-Shouldered hawk on a perch close to the boardwalk at Green Cay, only to find I focused just behind the bird for everything I shot.