best autofocusing bodies and lenses

[jhpeterson]

I'm an outdoor sports and action photographer, been one for well over 25 years and used Canon gear for nearly as long. While have a reasonably well-stocked camera bag or two, my present go-to body/lens combination is a 1DS3 with a 300/2.8. I'll often use an EF 1.4x (II) converter when I need a bit of better reach and once in a while the 2x when I'm in a pinch.
The 1D series bodies have been my standard for nearly ten years, and I really appreciate their rugged build and weather sealing (almost a necessity in my line of work). I favor 1DS over the 1D (and I've had both) for the higher pixel count (I bought mine before the 1D4 came out) and that I sometimes need a full-frame body for wide-angle interior/architectural work. 
What I use this most for are sailing and cycling events, where things are moving at relative modest speeds (say, no more than 10-20 meters/sec), but occasionally I cover powerboats, auto racing and air shows.
I'm in the process of upgrading some equipment, likely a body (it doesn't HAVE to be full-frame, it could be a 1D or even a 7d) and possibly a long lens.  I'm considering all options up to 500mm.
Figuring that there's enough folks on here who have had experience with just about everything, what I'd like to know is what camera/lens combinations offer the fastest autofocusing and, more importantly, most accurate?

While I'm generally satisfied with my results (and I have print clients who often demand something that holds together for 2-page spread), I always feel I could be doing somewhat better. (Did I mention that my parents had high expectations for their children AND I went to engineering school?)

[Mt Spokane Photography]

The new generation of bodies have improved autofocus over the 1D III and 1DS III series, even over the 1D MK IV series, so its a matter of waiting for the 1D X or picking up a 5D MK III. 
 
They have basically the same autofocus, and its supurb. The AF is more repeatable as well as accurate with wide aperture lenses, it might be the best that is available.
 
The 1D X will have all the bells and whistles of a 1 series body, but the 5D MK III feels pretty solid.  One thing to consider, is that the 1 series uses a higher voltage battery.  This allows it to provide more power to the AF motor in your lens and it will move to focus more quickly.  Unless you are really pushing it, with fast objects zigging and zagging, the 5D MK III should do very well.

[jhpeterson]

Thanks for your insights. Considering that my work exacts quite a toll on my bodies, I'm not sure I want to spend $7000 for another one.
If I did, the 1DX would be the obvious choice. So, I'm considering (in no particular order) the 1D4, 5D3, 1DS3 (likely used) and 7d.
I'm a little hesitant about getting the 5D3. I have a 5D2 and find it a bit "fragile" for my tastes, or at least the situations I find myself in. I'm just not sure how well-sealed it is, an important consideration in that I'm around spray and splashes much of the time.
I'm told the 7d is actually more weather-resistant, with better autofocusing as well. And, since I'm usually working at 200 or 400 ISO, noise shouldn't be a problem.
The 1DS has been my favorite for several years, I've had them in different incarnations. They are great performers, reliable and rugged (though I have "trashed" a couple of them, too), but I suspect the AF is somewhat less quick (or as accurate) as some of the other choices. It works very well with the 300/2.8, but it works slower when a converter is put on (somewhat noticable with the 1.4x II and definitely so with the 2x)
The 1D4 could be a good choice. I've used one for a couple shoots with good results. I'm not sure how much more accuracy in focusing I gain over what I already have, and whether it comes close to the 1DX or 5D3.

I'm wondering as well what impact my choice of lenses bear upon the results. Since I use the 300/2.8 more than anything else, it's likely to be my most important consideration.
A 70-200/2.8 is my other workhorse. I just got the II version, but still suspect it doesn't focus as fast as my 300 does (more elements to push around). 
I have a 400/5.6 that I'll use when I have plenty of light and may want to travel a bit more lightly. But, I think the AF works more slowly than with other lenses, as my percentage of sharp shots drops at the same exposure settings.
I'm considering replacing it with another 400 (either a 2.8 or 4 DO) or maybe a 500, though almost certainly one of the older versions.
I should also mention I have 1.4x and 2x converters, both version II, that I use, though would likely soon replace the 2x with a III.
Based on your collected experiences, what I wish to know is what configurations work best, in terms of fast and accurate autofocusing (and maybe which ones I should avoid). While I already have some pretty good ideas, your recommendations would be most appreciated.

[neuroanatomist]

In terms of 'overall' AF performance, I'd stack rank the recent bodies as follows:  1D X > 5DIII > 1DIV > 1DsIII > 7D > 60/50/40D > 5DII > xxxD.

[jhpeterson]

Thanks, neuroanatomist for your analysis. (Might I surmise, both from your name and the substance of your posts, that's something you do best?)
Though, I would have thought the 7d might have been a better performer than the 1DS3 in real-life, action situations (given that it has both a newer sensor and processor) and maybe up there on the level of the 1D4.
What I'd also like to know, as well, is which lenses work best on a given body. Say, compared to my 300/2.8 (not the latest II model), how do the following rank up:   300mm f:4 (IS and non-IS), 400/2.8 (both I and II), 400/4 DO and the 500/4?
Also, I'd be interested in seeing how much effect the 1.4 and 2x converters have upon their focusing results, a little or a lot and do they affect some lenses more than others. And, does anyone notice any speed/accuracy distinctions betwen the II and III models?
And, just where would the 70-200?2.8 IS II fall in, by itself and with the converters?
I know, I've asked a for lot of information, but I thinks there's enough of you out there to have had experience in all these situations to give some meaningful results.
Thanks in advance for your observations.

[PhilDrinkwater]

In terms of 'overall' AF performance, I'd stack rank the recent bodies as follows:  1D X > 5DIII > 1DIV > 1DsIII > 7D > 60/50/40D > 5DII > xxxD.

I'd agree with that.

5d3 sealing is improved upon compared with 5d2.

[jhpeterson]

5d3 sealing is improved upon compared with 5d2.

That's good to know. I'm often afraid to use my 5D2 for much of what I do.
Not that I take it swimming, but I spend 100 or more days a year on boats. In my line of work, the gear sometimes gets a thorough thrashing. Even my 1D series models stop working on a few occasions, a couple times beyond repair.
If the 5D3 measures up to the sealing on them, now that's something I will consider.   

[neuroanatomist]

Thanks, neuroanatomist for your analysis. (Might I surmise, both from your name and the substance of your posts, that's something you do best?)

Part of my day job. 

Though, I would have thought the 7d might have been a better performer than the 1DS3 in real-life, action situations (given that it has both a newer sensor and processor) and maybe up there on the level of the 1D4.

Age isn't everything.    Canon's 1-series bodies historically get better AI Servo algorithms (the 5DIII is a departure), and also the 1DsIII has f/2.8 points scattered across the frame whereas the 7D only has the more accurate f/2.8 at the center point.  Those factors lead me to rank the 1DsIII above the 7D.

Another thing to keep in mind is that with the same lens, 1-series bodies focus faster than other bodies because the battery delivers a higher voltage, which drives the lens' AF motor faster (and a battery grip on a non-1-series doesn't help since the batteries are used alternately, not simultaneously).

What I'd also like to know, as well, is which lenses work best on a given body. Say, compared to my 300/2.8 (not the latest II model), how do the following rank up:   300mm f:4 (IS and non-IS), 400/2.8 (both I and II), 400/4 DO and the 500/4?

I'd approximately rank them as 300/2.8 IS II = 400/2.8 IS II > 300/2.8 IS = 400/2.8 IS > 500/4 > 400/4 DO > 300/4 IS = 300/4 non-IS.

That's splitting hairs - in real-world terms, you'd likely not notice a meaningful difference between any of the supertele lenses, and the 300/4's would be a little slower.

Also, I'd be interested in seeing how much effect the 1.4 and 2x converters have upon their focusing results, a little or a lot and do they affect some lenses more than others. And, does anyone notice any speed/accuracy distinctions betwen the II and III models?

The 1.4x TC slows AF by 50%, the 2x TC slows it by 75%.  Overall, the MkIII TC's are supposedly a little more accurate than the MkII's, but probably not relevant in acutal use.

And, just where would the 70-200?2.8 IS II fall in, by itself and with the converters?

The bare lens would likely slot in just behind the supertele primes for AF speed, a little faster than the 300/4.  TCs would have the same effects (50% and 75% slower).

In terms of 'overall' AF performance, I'd stack rank the recent bodies as follows:  1D X > 5DIII > 1DIV > 1DsIII > 7D > 60/50/40D > 5DII > xxxD.

I'd agree with that.

5d3 sealing is improved upon compared with 5d2.

Yep.  Relative weather sealing is: 1-series >> 5DIII = 7D > 5DII = 50D/60D.

[jhpeterson]

Neuroanatomist, once again thank you for your detailed post. That's exactly the information I was looking for.
Of course, I'd be interested to see if others would come up with a similar ranking.
In the past, I've had a few conversations with sports and action photographers about this very subject. Often what I observe gets somewhat steered by what I just heard. For nearly ten years I've almost exclusively used the 1D/DS models, in large part because of the very things you wrote about (though, weatherproofing and ruggedness are probably my most important considerations).
Many times, it's been suggested that a newer, though "downline" model might be faster and that smaller aperture lenses might actually be faster because there's less glass to move around. I tended to disagree, at least for lenses from the past fifteen or so years (before the days of ultrasonic, autofocusing was often somewhat slow). I go back to the days of manual focusing, and recall how much easier it was to focus a lens with a maximum aperture of f:2 or 2.8, compared to one that was f:5.6 or even 4.
I'd like to think that at least some of the premium we pay for the pro bodies and "fast" L glass goes for superior technology, the kind that shows its worth when one faces challenging situations. 

[KyleSTL]

In terms of 'overall' AF performance, I'd stack rank the recent bodies as follows:  1D X > 5DIII > 1DIV > 1DsIII > 7D > 60/50/40D > 5DII > xxxD.

I'm surprized that the 60/50/40D > 5DII.  I always thought the 20D through 60D had identical AF systems.

I'd approximately rank them as 300/2.8 IS II = 400/2.8 IS II > 300/2.8 IS = 400/2.8 IS > 500/4 > 400/4 DO > 300/4 IS = 300/4 non-IS.

But wouldn't 400mm f/2.8 IS II >> 300mm f/2.8 IS II+1.4x TC?  That's more of an apples-to-apples comparison and similar to framing the OP is talking about.

[neuroanatomist]

In terms of 'overall' AF performance, I'd stack rank the recent bodies as follows:  1D X > 5DIII > 1DIV > 1DsIII > 7D > 60/50/40D > 5DII > xxxD.

I'm surprized that the 60/50/40D > 5DII.  I always thought the 20D through 60D had identical AF systems.

20D and 30D are the same (9 points, only one cross-type point - in the center, with one f/2.8 line and one f/5.6 line).  The 40D got an AF update, to 9 cross-type points with a dual-cross (two f/2.8 lines and two f/5.6 lines) in the center.  The 5DII AF is based on the 20D's, but with 6 'invisible' AF assist points for Servo tracking, which given their tight spacing and the relaitvely weak algorithms, don't assist all that much.

I'd approximately rank them as 300/2.8 IS II = 400/2.8 IS II > 300/2.8 IS = 400/2.8 IS > 500/4 > 400/4 DO > 300/4 IS = 300/4 non-IS.

But wouldn't 400mm f/2.8 IS II >> 300mm f/2.8 IS II+1.4x TC?  That's more of an apples-to-apples comparison and similar to framing the OP is talking about.

True.  I was treating the TC's as separate, since they have a consistent effect on AF speed across lenses.

[briansquibb]

I suspect the 200 f/2 has been missed

[neuroanatomist]

I suspect the 200 f/2 has been missed

It wasn't asked about...

[Z]

Another thing to keep in mind is that with the same lens, 1-series bodies focus faster than other bodies because the battery delivers a higher voltage, which drives the lens' AF motor faster (and a battery grip on a non-1-series doesn't help since the batteries are used alternately, not simultaneously).

I've often wondered about what effect this has on the lifespan of autofocus motors. Presumably all EF lenses are intended for use with 1D bodies, but I can't help think that a 1D might be more likely to kill a weak lens motor, such as the 50mm 1.4. Apologies for the thread hijack, but I suppose it's arguably relevant...

[briansquibb]

I suspect the 200 f/2 has been missed

It wasn't asked about...

True - but in the context I think it is relavent to the OP requirements to sports shooting.

Apart from which I am thinking of getting one for that reason