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Old Oct 10, 2007, 10:07 PM   #1
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I have a realitivly new Canon 70-200 f2.8 IS. New being b stock from B&H - which is fully factory recertified - not a scratch or nick to be seen. You couldn't tell a new one from this one, but......this past weekend when shooting an event, a foot road race, 10k, using a 5D, images were not as incredibly sharp as I have come to get use to with this lense. It was a heavily overcastday, shooting at f2.8, and always at least 100th of a sec or faster. While the subjects were moving, they were jogging so I would have thought 100th of a sec would have been enough. Maybe this is where I am wrong, some however were at 320th, which is clearly enough. The shutter speed is running through my mind as a good possibility, but I can't help be alittle suspicious of the lense. There was no hunting for focus, I was clicking away. I've since played around with the lenseand all seems ok. But before I move ahead with another event, is there a method that the lenses can be checked to make sure it isfully and properly aligned? Service facility with some type of alignment equipment? Some test I can do?
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Old Oct 11, 2007, 6:52 AM   #2
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1/100 is somewhat tricky to get a sharp image of some moving object. Even 1/300 is sometime very tricky.

Eliminate as many variables as possible while testing a lens sharpness. Like moving subjects, very low shutter speed. It may just be due to the technique too. The IS is useful for any Camera/Lens movement. But when the subject moves the IS is not THAT helpful.

To test the lens i would advice a decently lit still object. Portraits are very good examples.

Please post a sample for others(Experts) to help u out here
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Old Oct 11, 2007, 7:41 AM   #3
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If you're getting sharp images with still or more brightly lit images, the problem is most likely shutter speed and/or operator related. 1/100 of a second is pretty slow for sports. It takes a pretty fast shutter speed to stop hand and leg motion. JohnG has some posts regarding sporting event shooting. I think the minimum speed is around 1/300 or 1/500 of a second.
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Old Oct 12, 2007, 5:47 AM   #4
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what focal length were you using? 1/100 @ 200mm is different then 1/100 @ 70mm
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Old Oct 12, 2007, 11:41 AM   #5
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Shooting plenty of different sports myself, there are a couple of basics to remember if your wanting crisper photos.

If you close up your apperture from 2.8 to 3.5 or more, your pictures will be sharper. Also 1/100 shutter speed is too slow to freeze running. Three ways to boost your speed to 1/500 or greater is to increase your ISO's, shoot jpg's a stop or two (no more than this) darker in your exposure. I believe if your shooting RAW you can go 3 stops darker and lighten later with no pixel damage and lastly, use flash.

Boosting ISO's and darkening exposure is going to increase color noise but if you have the removal programs for this then noise clutter is not an issue.

When I shoot indoor sports where the lighting is less than desireable I still shoot ISO's at 3200 and use the 580 ex flash. For me, shooting indoor swimming, I need to push the camera limits in order to achieve at least a 1/640 to freeze this type of action.
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