Kenko Pro v Canon converter test Results (1 Viewer)

[postcardcv]

sorry to sound stupid but why wont a camera af past f8?

As the aperture of the lens gets smaller (bigger f number) the light getting to the sensor is less... less light means slower and less acurate AF. So camera manufacturers will limit the system so it will not even attempt to AF if the max aperture is smaller than f5.6... using the taped pins trick you can fool a camera into thinking it's using an f5.6 lens when it's effectively using an f8 set up... above that and a standard body will struggle. Using my lenses and tcs (with pins taped) I've shown that my 400D will actually AF perfectly at f6.3, fairly well upto f8, but at f9 it is hopeless.

 

[stevetb]

so with a lens of f4.5-f5.6 it will be alright?

 

[postcardcv]

so with a lens of f4.5-f5.6 it will be alright?

a f4.5-5.6 zoom will certainly work fine on it's own, however when adding a tc you can get variable, but it would be worth a try...

 

[stevetb]

thanks very much postcardcv. I assume the aperture af thing is the same on all enthusiast dslr's, its just canon camera's actually wont let you, rather than letting you try, and failing ( if you know what i mean). Mike from ebbw has had some very good results with a tc, however i dont think i will be getting one yet - but i should be getting my new gear very soon!