jkurkjia wrote:
bwhip62, FWIW the picture above is your only posted example with the action coming towards you ... I hope you are aware that it\'s front focused. The other examples have the target moving perpendicular to the optical axis; these do not represent a big challenge to any AF system provided you are doing a decent job of panning (which you are).
I\'m not trying to burst bubbles here ... just a suggestion for you to rethink your test (and of course the results) while your new camera is still within the exchange period.
To test the basics of AI Servo AF I would suggest shooting the family car coming towards you at 25 to 30 MPH (i.e. speed limit in your neighborhood); the car is a repeatable target that you can use to retest AF tracking performance using any/all of your lenses and/or bodies.
Regards,
Joe Kurkjian
Thanks, Joe.
I\'m still testing for sure, in a wide variety of different applications and conditions. Because my primary use for the camera will be in shooting motorsports, having outstanding AF tracking is critical.
I took several hundred shots that day, some better than others of course. There are so many different customization options with the camera, that it is difficult and time-consuming to test them all in a controlled and scientific manner. I can look at a shot later, and not be 100% certain whether the lack of focus where I wanted it to be had to do with a CF setting, or something different (aperture, shutter speed, me not holding the camera steady enough, me not tracking the subject properly, etc.). In the limited amount of testing I\'ve done so far, I\'ve also noticed that AF on moving targets works better with some lenses than others. I haven\'t yet had a chance to do much testing with my 600mm f/4, which is very important as I use it quite a bit in my motorsports work.
In shooting the dogs, sometimes their actions are unpredictable. I\'m moving the camera, panning along with their movement, trying to keep the focus on them as their heads move up and down while they run, when suddenly they stop or turn. It\'s probable when they are running toward me that the focal point is trying to zero in on their head, and then their chest.
I do see a tendency on shot of them running toward me for the camera to front-focus. I picked that photo probably more because I liked it than because it was the best representation of AF. The general results from this particular day\'s testing were so much better than the previous, that I felt reassured.
Here is a complete sequence of photos of a dog running toward me that came from that session. These are all uncropped, just reduced in size.
I\'ll definitely keep testing! I sure want this camera to be all that I expect it to be, especially considering the considerable investment involved. Thanks again.
Feb 11, 2010 at 10:26 AM
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