Need repair on 1D Mark 3, any suggestions?
Hi,
I'm having focus issues with my 1D III. It is in the range of serial numbers affected by the recall, but Canon is telling me they are no longer servicing the 1DIII, and I am out of luck. The focus only seems to be affected during action shots, and result in out of focus shots probably 40% of the time. Is there another repair vendor that I can use to repair this? Thanks!
I'm having focus issues with my 1D III. It is in the range of serial numbers affected by the recall, but Canon is telling me they are no longer servicing the 1DIII, and I am out of luck. The focus only seems to be affected during action shots, and result in out of focus shots probably 40% of the time. Is there another repair vendor that I can use to repair this? Thanks!
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Not really new. Admittedly, I've been putting off sending it in; I didn't know there was a drop dead date on DIII repairs. I tried using AI and it seemed to be worse. Also, these were taking indoors, shooting hockey, with a 135L always wide open.
The first thing I recommend is to take some time to learn about the AF system of the Canon 1D Mark III. The custom function setup for the 1D-MIII is rather a handful, and nothing at all like the 5D you had before.
First, check out this PDF article: http://www.the-digital-picture.com/Information/Canon-EOS-1D-Mark-III-1Ds-Mark-III-Optimizing-AF-Settings.pdf
(Download a copy to study.)
Also look at:
http://cpn.canon-europe.com/content/education/technical/mkiii_af_tips.do
http://cpn.canon-europe.com/files/product/cameras/eos1dmark3/EOS_1D_Mark_III_Guide_to_AI_Servo_AF_Custom_Functions.pdf
Note that Canon has some "Custom Function Sets" recommendations by shooting scenario. These should be pretty good starting points. Test with the recommended settings first, then make changes one custom function at a time. See what yields the best results for your particular situations of lighting, action and scene.
The Canon EF 135mm, f2L USM, shot at f2 is nearly impossible to shoot action sequences with a high keeper rate. The DOF is so amazingly thin* at that aperture, that alone explains most of your issues.
Indoors and a hockey game complicates things further. Indoors means that there is less light, both for the exposure and for the AF module. AF sensors are just a specialized kind of CMOS imager, and they are sensitive to the amount of light. In less light they are less sensitive because of fewer photons of light hitting the sensor, compared to good light.
Indoor lighting also has a "flicker" rate, and older lighting is typically the worst flicker with a slower rate and stronger effect. Sometimes you can even hear the "hum" from the lighting, typically at 60 hz or some multiple of that rate. While the lighting flicker will also affect exposures, both in intensity and in color tonality, the AF problems it can induce are a real cause of missed focus.
Hockey games also have a lot of subject distractions, with players cutting into and across the image frame, and players changing direction, which causes the AI Servo predictions to fail. (It's not possible for an AF section of "any" camera to accurately predict focus during subject motion changes, and/or distractive matter. AI Servo only generally works well with subjects moving at a relatively constant rate towards or away from the camera.)
I almost forgot about the glass/plexiglass protective shield, which often has marks on it as well as being somewhat reflective, both of which can throw off AF.
So there is the most likely cause of most of your AF problems; the situation and the circumstances of the shoot:
A large aperture with little DOF for focus error.*
Reduced light reducing AF sensitivity and speed, and likely flickering light at that.
Subject distractions from other players on the rink.
Shield to shoot through.
Given all of the above, an AF success rate of 60 percent is probably not too bad at all. Actually, that means you did "your" job in tracking the subject pretty well.
I do recommend that you try an aperture of f2.8 for the same circumstances. That will increase DOF and should increase the keeper rate as long as you can keep the shutter speeds up, generally by increasing ISO. Also decrease the C.Fn III-2 to "moderately slow" or even "slow".
*(At 50 ft to the subject, and with a crop 1.3x body [Canon 1D MkIII] and 135mm lens at f2, the DOF is less than 4 ft. At 20 ft, DOF is 0.6 ft, and at 10 ft it's only 0.15 ft/1.8 in.)
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