Don Clary
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Buy and Sell: On
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 p.1 #1 · 500 f4, 5D vs 1D2 auto-focus | |
It has often been stated that 5D auto-focus is GREATLY inferior to Series 1, that 5D is not suitable for wildlife photography.
A related idea is that Series 1 will do standard precision auto-focus up to f8 and high precision up to f4, while the non-Series 1 bodies require f5.6 and f2.8 respectively. Since 500mm f2.8 lenses are quite a rare breed, this implies a considerable sharpness advantage using Canon 500 f4 and 1D2 vs Canon 500 f4 and 5D.
Since I own this lens, and shot both bodies every single day for 3 months on Yellowstone wildlife, I decided to prove this to myself. I specifically constructed tests to prove that the 5D was inferior in auto-focus and consequently inferior in sharpness.
My first test was high contrast light, high contrast subject, one shot mode with center focus point selected. I photographed a brown Yellowstone sign with white lettering in full sunlight at f4 at about 200 feet. The lens and body were mounted on a Gitzo 1410 aluminum tripod with full Wimberly head. This tripod/head combination weighs 12 pounds and is only slightly inferior in steadiness to a 200 pound concrete block.
I shot a series of auto-focus tests, each time manually focusing the lens at 20 feet, and forcing the lens to auto-focus at the 200’ distance. After trying this many times with each body, I shot the same series again doing manual focus, as a baseline for lens sharpness. I examined all of the center crops side by side in Photoshop at the same time. The result was, even at 100% pixels, there was no difference sharpness from either body, with the lens at f4. I had failed to prove that 5D was inferior.
O.K, back to the drawing board. I selected an extremely low contrast target, on a low contrast, snowy overcast day. I selected an area of weathered brown wood of an old building. I set both bodies to AI servo, with center focus point selected. I realize I was shooting a static subject in a motion auto-focus mode, but I wanted to prove AI servo was much better in Series 1. I shot a similar series of pictures, forcing the bodies to refocus for every single shot. When examined at 100% pixels, the 1D2 pictures were very, very slightly sharper. Let’s say if the 1D2 was 100% sharpness, then the 5D was about 95% as sharp. I don’t think this difference could be seen in a 16”x24” print, but I did not print them; probably should have. O.K. I failed again to prove the 5D was inferior in auto-focus.
The next test was two days of shooting birds in flight at Bosque del Apache, New Mexico. I was using the 500 on the Gitzo, with the Wimberly head loosened for tracking the bird’s flight. AI servo was used, with center point selected and adjacent points enabled. In initial focus acquisition, if the 1D2 locked on in 1 unit of time, the 5D took 1.2 units. If I lost focus by letting the center point drift off of the bird, the 5D took 2 to 2.5 times as long to re-acquire focus. So I saw little difference in focus speed, if I was able to keep the center spot continually on the bird. Sharpness, after both bodies had locked on the bird, seemed to be the same.
I preferred to shoot Bosque in single frame mode, not a 8.5 frames per second, since there seemed to be one split second in time where the bird was closest, and correctly framed. I prefer to time the exact, correct moment, and not just machine gun it. This also has some benefit in editing, since even my slow shooting resulting in too many pictures to edit. The 1D2’s lightning fast frame rate and shorter black-out time was quite noticed and appreciated, but I didn’t see that this resulted in any better pictures. I judge a camera by the result it produces in the final print, and not on what an awesome machine it is. A camera is like a screwdriver or hammer, it’s just a tool on the way to the final result.
I discovered one slight advantage of the 5D, in birds in flight, only at home after the shoot. I tried the fill the frame as much as possible with each body for maximum picture quality. But accurate tight framing is quite difficult with the birds twisting and turning. If the bird perfectly filled the 1D2 frame, the 5D, at the same distance, could be cropped to equal quality, since both bodies have the same sensor pixel density. But a wing clipped off on the 1D2 would ruin the picture, whereas the wider field of the 5D might have captured the entire wing.
I did not save the pictures after this series of tests. Anyone with this super-telephoto and both bodies could try to duplicate the test. I think my auto-focus results, specifically at f4 on a super-telephoto, are quite interesting.
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