Well, I just dropped my repackaged Mark 3 off at my shipping dock with a RMA number to B&H. I've shot all kinds of stuff in AI Servo mode, with mild success, though not as good as my Mark IIn.

SN: 524xxx

The real killer, however, was one shot mode. I could not get consistent results, not matter what I did. I've included a series of shots that I took of a cooperative duck that I came across. I used two lenses in this test: an 85 1.2 II and a 200 1.8. I think people would agree these would be considered decent lenses. The 85 was micro-adjusted for a very minor back focus and the 200 was spot on.

Given the fact this duck didn't move, I was able to pretty much do what I needed. I took screen shots from ZoomBrowser with the focus points and exposure information included. While the images are downsized substantially, it doesn't take a rocket scientist to see the problem. Sometimes the lens would front focus, sometimes back focus, and very occasionally I might even get one in focus! The front/back issue was with both lenses. The 200 shots were at f3.5, and the 85 were at f4.0, with one at f1.6 to maximize the effect.

Image 1 - 85mm f4.0, front focus
http://www.norcostco.com/mark3/85-1.JPG

Image 2 - 85mm f4.0, back focus
http://www.norcostco.com/mark3/85-2.JPG

Image 3 - 85mm f4.0, back focus
http://www.norcostco.com/mark3/85-3.JPG

Image 4 - 85mm f4.0, back focus
http://www.norcostco.com/mark3/85-4.JPG

Image 5 - 85mm f1.6, back focus
http://www.norcostco.com/mark3/85-5.JPG

Image 6 - 200mm f3.5, back focus
http://www.norcostco.com/mark3/200-1.JPG

Image 7 - 200mm f3.5, front focus
http://www.norcostco.com/mark3/200-2.JPG


Summary
1.) One shot AF mode – Using both an 85 1.2 L II lens and a 200 1.8L lens, the camera cannot achieve consistent focus using either single selected AF points or using the default set of AF points. The following items have been tried:
a. Micro adjust of both lenses. Both lenses are adjusted fine. The AF problem is not a consistent front or back focus issue – it is random, sometime front focusing the image and sometimes back-focusing the image, and very rarely achieving the desired level of focus.
b. Custom function 3-8, AF Expansion set to either 1 or 2 does not help the situation.
2.) AI Servo mode – A similar effect exists using Servo mode. There is not a consistent focus pattern to any series of shots. AI Servo did seem slightly more accurate than one shot.

I would expect a 100% keep rate on any of these shots with any of my other cameras. They are simply easy shots, period. While many of the shots are “close” to focus, this camera is simply not a tool that I can use in my profession. I own and shoot a 1DMk2n ,a 1DsMk2, and several 20Ds. This camera’s AF system, while very fast, is not as accurate as any of the cameras above. This is not an acceptable level of performance from a professional grade camera.

Other than that, the camera rocks! Low noise, beautiful build and a great control layout.

Thanks, but I'll wait.

--
Carbonman

Flame alert: I wear Ztex underwear so if you flame me, not only don't I care, but you can't toast what matters.