I found the Mark III's autofocus performance to be similar to other EOS D-SLRs, but that was not a universal experience. In the not-so-distant past some of my Canon-shooting friends reported having problems with achieving sharp focus with the Mark II when shooting lenses wide-open, especially with the now replaced and upgraded 16-35mm f/2.8L lens. The fix was to send both camera and lens back to Canon repair, who would "tweak" the lens/body combination for optimum sharpness. Sometimes it worked, I am told, and other times it did not. Hence the new "II" lens, but somebody decided to take it one step further and add Custom Function III-7 "AF Microadjustment" to the Mark III that lets you make fine adjustments to the AF's point of focus in plus or minus 20 steps. The User's Guide warns that "normally this adjustment is not required" and I didn't feel a need to use it because it also warns that "doing this adjustment may prevent correct focusing from being achieved."

What's this slightly out of focus image doing in this review? It's calling attention to the fact that some websites have reported AF problems with the Mark III and while even one of my sports shooter friends had these kinds of problems with the very camera I tested, my own extensive testing (hey, I'm not Consumer Reports) showed the Mark III's AF performance to be superior to my personal Mark II when photographing these same kinds of moving subjects.

Shortly after the introduction of the EOS-1D Mark III there was buzz all over the blogosphere about autofocus problems. Because Shutterbug reviews reflect a mature perspective and not just scoops, our editor asked me to take the time necessary to check out this potential problem and the first thing I did was ask a sports photographer friend whose work I admire to shoot with the camera. He did this with me present one morning by shooting relatively slow-moving cars in traffic and decided "the camera did indeed have serious problems. Very few frames per sequence were sharp." I repeatedly asked Canon U.S.A. for an official comment about the alleged AF problems but none was forthcoming as this story went to deadline.

As I mulled over this lack of performance it just didn't seem right so I went back to the very same spot and recreated the same AF test with a few differences. This time I brought along my personal 1D Mark II to give a direct heads-up comparison. All shots were made in Manual mode using the same lens, an EF 70-300mm f/4-5.6 IS USM. In Single Shot AF mode 58 percent of the shots were in focus with the Mark II. When I switched to Continuous AF the number of in-focus shots dropped to 56 percent. Next, it was the Mark III's turn. In Single Shot AF mode 82 percent of the shots were in-focus with 90 percent in-focus while in Continuous AF mode. Under these conditions both cameras produced what many would consider an acceptable amount of in-focus shots, but the EOS-1D Mark III's performance was nearly perfect.

So what do I really think about the Mark III? To paraphrase the question Tom Hnatiw (www.dreamcargarage.com) asks about modern supercars: Do you need a camera like this? While the EOS-1D Mark III is far from perfect, it delivers the kind of stunning image quality that professional photographers demand and their clients expect.

With apologies to my friend and the blogosphere, my take on the AF allegations is similar to what the late Señor Wences often said: "Is difficult for you; is easy for me." If you shoot sports, the 10 fps burst rate gives you an edge in capturing that one split second that makes the difference between a good shot and a great one. Every pro or aspiring professional will want to upgrade to the Mark III as their budgets permit, which are the keywords here, and as their assignment needs dictate. Do you want a camera like this? Oh yeah! With a price tag that's similar to the Mark II N and capabilities that far exceed it, the EOS-1D Mark III, priced at $4499, is a bargain for serious shooters.

What Else Is New?
The EOS-1D Mark III's Live View shooting mode lets you focus and compose on the 3" LCD screen and even magnify the image five or 10 times. In a studio the camera can be connected to a computer running EOS Utility 2.0 software, allowing you to view what the camera is seeing in real time as well as control its operation. If you work with remote cameras, the Mark III can be operated wirelessly with Canon's new Wireless File Transmitter WFT-E2A. This device lets you view images from the camera's sensor in (virtually) real time along with the ability to adjust camera settings on the fly.

Everybody hates cleaning image sensors so the camera's Integrated Cleaning System should help; indeed, dust specks were not a problem during my tests. The CMOS image sensor is covered with infrared absorption glass that uses a "shake your bootie"

self-cleaning system different from the EOS Digital Rebel XTi. You can also clean the sensor by selecting Clean Now in the camera menu. The process takes 4 seconds and during that time ultrasonic vibration is applied to the infrared absorption glass and the shutter--now upgraded to 300,000 cycle durability--is cocked three times so dust falls off and any debris resettling on the curtains is also shaken off. The final piece of the anti-dust puzzle is software that records the location of any remaining spots as Dust Delete Data and appends it to the raw or JPEG file in the IFD portion of the file header. When using Canon's Digital Photo Professional 3.0 software, any remaining spots are automatically erased.

Mark II Vs. Mark III
When I tested the Mark II for Shutterbug, I photographed Jaguar Mark II automobiles. The stylish Mark II appeared in many films but was most notable in the PBS TV series Inspector Morse. There are no Mark III Jags; the company followed the Mark II with (what else?) the Mark IX. The Mark III on the other hand was a popular Lincoln automobile whose most prominent screen appearance was as a pimpmobile in Roger Moore's first turn as James Bond in Live and Let Die. I asked the local Triumph club for owners of Mark III Spitfires to come forth to be photographed for this review, but nobody volunteered.

I tried to find a Mark III Spitfire to photograph but had to settle for this rusty Datsun. Before Nissan cars bore their maker's name they were called "Datsun" and this 1600/2000 has seen better days and was photographed with a Canon EOS-1D Mark III and 16-35mm f/2.8L zoom lens. Exposure in Program mode was 1/400 sec at f/10 and ISO 200.