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AF performance of the ef 300mm f2.8 ii with the ef extender iii

HappyHammer
Apprentice

I own a 1DX (the original version), ef 1.4x extender ii and 2x extender iii and 300 f4 is. 

The AF works well with the 1.4x. With the 2x I only get 4 AF points, so tracking birds in flight is difficult, particularly when the subject is small in the frame. The 2x works well with static subjects.

How does the AF perform with the ef 300mm f2.8 i or ii compare? How many AF points would I get with either version? I'd also be interested in the AF speed.

I'm interested in the 300 f2.8 for indoor sports and hand held bird/wildlife photography, hence I wasn't looking to get a longer telephoto if possible and was interested in the 2x extender performance.

Would appreciate any feedback.

 

2 REPLIES 2

wq9nsc
Elite
Elite

I no longer have my original 1DX but the manuals for the 1DX II and 1DX III indicate no difference in the pattern or type of focus points available whether you are using the version 1, 2, or 3 of the 2X converter with the EF 300 f2.8 IS II lens. 

So I seriously doubt if the type III 2X will offer any better functionality with the original 1DX and you would still be limited to the small number of points in the center of the array.  The original 1DX AF sensor was severely limited once you moved beyond a f5.6 capable lens.

And I really like the 300 f2.8 lens, incredibly sharp and fast focusing.  I bought it before I bought my 400 f2.8 and it still gets some use.

Rodger

EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video

p4pictures
Authority
Authority

With the 300mm f/2.8 lens and 2x extender you will get all 61 points selectable for AF and the central block of 21 point will be cross type AF points. Ultimately this is because the combination of lens + extender give an aperture of f/5.6. It is the combination of the 300mm f/4 and 2x extender that drops to f/8 and only the central four points.

I found a PDF manual for the EOS-1D X and this info is on page 78. 


Brian
EOS specialist trainer, photographer and author
-- Note: my spell checker is set for EN-GB, not EN-US --
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