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Topic: Older EF lenses with new EOS (Read 4765 times)
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Goran
Newbie
Posts: 2
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A few month ago I bought a EOS 7D for bird photographing and have been using it with my old EF300/2.8, non IS, mostly with 1.4 or 2x extender! I often experience that the AF can be very tricky to handle in situations with moving object like flying birds, and some time don't find focus at all. As I earlier have been shooting with an EOS 1D mkIIN I first thought maybe the AF in the 7D didn't match the one in 1D, but I think it is something else. I have got some information that the new AF-system in the 7D, probably other newer models as well, can give the older lens "too much" information and the AF will not work properly! This explanation seems to be applicable in my case!
Have anyone else expeirenced the same problem when using older EF lenses!
Is it possible to minimize the problem with some settings in the camera!
Have anyone compared the the 300mm2.8 with non IS with one with newer version with IS, especially considering AF with moving object.
Goran
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Bob Atkins
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I can't answer your question because I've never tried the old 300/2.8 on a 7D, but I doubt that there's "too much information" sent to the lens. The camera does all the heavy work and contains all the AF "smarts". The only signals it sends to the lens are ones which move the USM motor.
I would note that the AF system of the 1D series cameras is designed to work down to f8 (with the center AF zone) and that of the 7D only down to f5.6. I know with a 2x the 300/2.8 is f5.6, so a 7D should handle it, though maybe the 1D is a little better since it's not as close to it's working limit? Just a guess, I have no evidence to support the theory!
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Goran
Newbie
Posts: 2
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Ok, thank you very much!
I think I have to start by trying to shoot with the same lens and extender with my 1D mkIIN again just to verify that´s nothing is wrong with the lens!
Goran
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marcfs
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The 7D focusing system is excellent and requires new learning and an investment of time to master. Artie Morris has written a 7D users guide that might be helpful for you. https://store.birdsasart.com/shop/item.aspx?itemid=285 I have been able to capture more BIF images with the 7D then my 40D. Good luck!! Marc |
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