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

[HappyHammer]

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.

[wq9nsc · Accepted solution]

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

[p4pictures]

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. 

[HappyHammer]

Thanks. I didn't realize this detailed info was in the manual. It certainly confirms the 4AF points I saw in the 300mm F4 + 2x.

[ebiggs1]

My limited use of the ef 300mm f2.8L (my good friend George has one) is, it tolerates the 1,4x pretty well. I admit as a tel-con hater that combo works. It even works on the ef 300mm f4L very well. I even recommend that combo.

By itself the big 300mil 2.8 is wonderful so why do you want to compromise that great IQ with a 2x because all, every, tele-con hurts the IQ. IMHO, you would be better served getting one of the Sigma or preferable Tamron (G2) super zooms.

I almost never use anything but the center focus point so the loss of any is of no problem for me. I have no idea what the manual says as I don't think I have ever looked at it!

[HappyHammer]

Thanks for the feedback. I am considering the 300mm f2.8 for sports photography in addition to bird and wildlife photography. I would like the extra stop to keep the ISO at 5000 or less without dropping much below 1/1000s. All the reviews state the IQ and AF speed are second to none. I would anticipate using without an extender a lot. I can certainly live with the F4 since I not pro sport photographer, it's a nice lens. When I use the 300mm for indoor Volleyball I'm generally pre-focussed on a hitter or blocker at the net from the back of the court so the AF speed isn't that crucial. Also for those shots I can reduce the shutter speed a little. I'm hoping to spend more time on other sports where the AF speed may be more important in the future.

I will take a look at the Sigma and Tamron recommendations. Before posting, my general impression of these big zooms was that the IQ would not be a good as a prime, it wouldn't be fast enough for sports particularly in low light and for wildlife/birds I would often be close to 600mm. However I will re-evaluate. Perhaps they will give better IQ than the 300 f2.8 + 2x.

Given the cost of a used 300 2.8 in good condition, renting one and trying it with and without the extenders would be wise move. 

[ebiggs1]

OK since you are talking used my recommendation is the Sigma 120-300mm f/2.8 DG OS HSM Sports Lens. I never recommend a 2x tel-con but that's up to your and what you are good with it would not be up to my standards. I shot volleyball for a while and I found the 300m too long as in way too long but there again all depends on what you want and need. I used my ef 85mm f1.2L a lot for volleyball.

IMHO, 300mm is too short for birds and one of the super zooms preferably the Tamron G2 would be my choice and is. Don't get put off by the f-stop numbers although it looks like a big step. going from f2.8 to f5.6 is just two stops. It ain't no big deal. I use mine indoors all the time. And 600mm is way better for birds.

BTW, the Sigma 120-300mm f/2.8 DG OS HSM Sports Lens.handles its 1.4x tel-con fairly well too. There is no doubt the big Canon ef 300mm f2.8L is the shartpest so putting the tel-con on it is a shame to inhibit that fantastic IQ. As a general rule zooms are never as sharp as primes.