Crex Test of Mark III

(Correction below.)

With my 1D Mark IIn in the doctor’s waiting room in New Jersey to get a diagnosis of what ails its focus system, I took my new-to-me Mark III to Crex Meadows yesterday to see if it would take a picture or two. It did, which is why I’m here telling you the story.

From the day the stork dropped it in camera stores around the world, the Mark III has been plagued by 1) focusing issues, especially in bright, warm and/or back lit conditions; and 2) a less than stellar response to said issues by Canon. I came within a key stroke of buying one when it first came out, and boy am I glad to have hesitated. The Mark III has been recalled three times that I’m aware of, and has seen multiple changes in firmware. The photographers I respect most — photojournalists who shoot under every condition imaginable — say it’s much, much better but still isn’t fixed. After sending my IIn for repairs I decided to find out for myself when I found a barely used Mark III in mint condition at a good price. Yesterday, I took it to Crex Meadows for some testing (and to escape the madding crowd). So, IMHO, is the Mark III 100 percent absolutely, positively fixed? No.

In one shot mode with only a single focus point selected, the Mark III grabs accurate focus immediately and locks it down. The resulting image is as sharp as anyone could want. This flycatcher was taken with the 500/1.4x combo . . .


. . . and cropped from this image:


I certainly can’t complain about the quality of the resulting image.

But turn on AI servo and the story changes. Here’s a stationary, back lit cedar waxwing shot using a single focus point and AI servo. (It’s another big crop.)


Ugh. I have about 20 images I shot of the same bird in AI Servo. None of them are better than this.

I flipped over to single shot and got this.


I have about 15 frames in single shot, and all are like this one. (Note: I sharpened the lower image but forgot to sharpen the top one, but no amount of sharpening is going to hide the missed focus.)

In situations where the subject was larger in the frame and not back lit, AI servo worked fine, such as with this preening trumpeter swan. This was also in single shot. My AI Servo images of this swan are distinctly softer.


It also appears that turning on the helper points around the chosen focus point makes things worse in any situation in which AI servo is used. I say “appears” because I didn’t shot enough in that configuration to come to a firm conclusion.

More to come when I know it. I’m hoping to get back to Crex Sunday to get some panning and tracking shots of sandhill cranes.

One Response to “Crex Test of Mark III”

  1. ivars krafts says:

    Thanks for your report. I'm looking forward to more. I have been tempted to switch to Nikon, but have too many lenses to consider doing that — I think.