Yes, Rob says Canon has lost its autofocus mojo. Yesterday I went to the Rob Galbraith web site and downloaded the six zip files with the more than 900 images. I looked at ALL the images, for over 2 hours. I looked closely at the sequential shots, and the Mark IV performed very poorly under situations where I would expect a pro sports camera would excel. Considering that Canon provided Rob with a calibrated 1D Mark IV body and multiple calibrated lenses, and Rob bought a body, and also used two borrowed 1D IV's, the results are hard to stomach.
Each photo has the AF points selected in red overlayed, and the blue ancillary "assist points". Each image has pertinent EXIF info overlayed on it. As a poster above said, with his 40D in AI servo he was averaging a 70% keeper rate. Well, the one-month-long test across multiple sports has nowhere near the kind of keeper rate I expect from my D2x and 70-200 VR, 200mm f/2 AF-S, and 300mm f/2.8 AF-S. Seriously...I thought Rob was exaggerating and being extremely hyper-critical when he wrote the conclusions. But then I looked at the images; he was not overly-critical.
The thing is--the blogger reviews are all ONE-event, one-off deals, in lower light levels--San Francisco afternoon football the third week in December, indoors one night at a dingy, really dingy sports center with athletes wearing walking autofocus targets in the form of lacrossse uniforms with a 6 foot long stick, plaid side panels, gloves with cross-hatching on the sides, a white helmet with facemask: in other words, walking,running High-Contrast targets. Let's be honest: the 1D Mark III was lauded by Rob Galbraith as being the FASTEST-EVER LOW-LIGHT one-shot INITIAL AF acquisition. That is what Rob said when he tested the 1D Mark III in 2007--truly superb, class-leading world-class initial acquisition, especially in low-light. But the Mark 3 had problems with sequential autofocusing,and as light levels went up, the Mark 3 got worse and worse in terms of AF performance in sequential shooting and on STATIC targets.
I downloaded the 900+ files in zip form, and went through them last night. Unlike a one-hour "test" at one or two low-light venues or on baseball, which is a DEAD-easy AF sport, with action occurring at pre-determined locations, the sample sports assignments Rob and Mike Sturk shot were designed to keep the AF point on the athlete and see how well the camera can acquire and track focus...in all situations. Early morning slanting light; afternoon front lighting; back- and side-lighting, at night in the rain, indoor basketball, and indoor speed skating at the brand new Olympic venue. The 900 shots show many,many **Sequences** shot with pro-quality, Canon-serviced L-glass 70-200,300/2.8,and three different 400/2.8's. It's one thing to see 1 or 2 or 3 "selects", but looking at sequential shots, many of them, in all types of scenarios over 30 days...with 1 Canon-calibrated body, 3 Canon-serviced lenses, and three "other" bodies, and THREE different 400/2.8 lenses, from both the 1 and II generation...being shown the entire sequences reveals a huge amount about the way the AF system works
But do not take my word for it. As Rob suggests, "see for yourself."
Rob Galbraith DPI: Seeing for yourself
