First, thanks for cleaning up after my mistakes...no excuses, I did know about the 400mm's long MFD and the 70-300mmL incompatibility with extenders, at one time, and had forgotten them. Of course, I would expect and hope somebody would remember that a f/5.6 lens is not going to play nicely with teleconverters before they buy it, but the option is still out there and when used within limits it has gotten great reviews.
'Beaten' is relative.
Just to make it obvious where I'm coming from, this
is the major review I've based my thinking off. Even at f/11 the 100-400 is still far below what I'd consider to be par.
Of course, close up wildlife actually is much kinder to lens sharpness than many people would expect...and not being able to focus closely is a problem. I have seen perfectly good pictures taken by the 100-400mmL. The 1998 400mm prime sits uncomfortably in the lineup - no aperture advantage, no closer focus distance, no weight advantage, and of course no IS - the first three points conspire strongly to make it a poor choice for wildlife shooting up close, but (in my personal opinion) the 400mm length is not great for much of the distance wildlife shooting (that I do). I can think of many uses for it, but bird or small wildlife photography isn't one of them - though the faster focusing (which I have heard about before) would again put a damper on uses of the 100-400mm.
About my grievance with the 400mm focal length - I usually find it a good length for group portraits - of groundhogs, and other small animals close by! - but not the usual single bird photography often seen. Both these lenses are limited to f/5.6 at the max aperture - for most of us, that means we're done, no more improvement can be had with teleconverters (without sacrificing quality at least). 600mm is a much more useful focal length for me - at all distances, too. The f/2.8 zooms are flexible in this regard, but it's for that reason that I am happy enough to deal with a teleconverter for the Sigma 120-300mm f/2.8 OS - a 240-600mm f/5.6 lens is very useful indeed. It's close, though certainly no match or replacement for, the upcoming Canon 200-400mm at the same focal lengths (although no teleconverter switch is needed to move to the 400-600mm-ish range, the f/4 aperture on the coming Canon is nice). I haven't gone and tested minimum focus distance reduction with a 2X teleconverter, but the 120-300mm goes from 1.5m MFD to 2.5m when moving from 120mm to 300mm focal lengths - a bit longer than the 70-200mm but not by far, and I think the focal length will let you feel closer (and enjoy more of the defocus area effect) even from a slightly further (compare 59.1 inches against 47.2 inches) minimum focus distance. The teleconverter won't hurt this specification - so it seems to me proof that, if Canon had its act together, one can have multiple great specifications in the same lens. It is hard to argue against the stable (and actually falling) price of these lenses, though.
But then that takes us back to the issues of flexibility and price - Canon simply ought to update the 100-400mm, no question about it. The 70-200mm's weight doesn't seem too bad, but for my money - when I'm already looking at $2500 for a 70-200mm IS II, and $500 for a teleconverter, another $500 to get an extra 100mm (to 300mm) on the long end, and go from a very so-so 400mm focal length to a much better 600mm focal length seems adequate.
Of course, that doesn't wipe out my personal frustrations with the autofocus, the odd refusal of the optical stabilizer to kick in at the right times (sometimes), while I do get sharp captures down to 1/60 second even at 600mm, and sometimes even lower (I think I've gotten one handheld down to 1/8 of a second, somewhere!), I definitely would say that it hasn't quite earned the bulletproof reputation of the 70-200mm IS II yet. With a better body...if only. One can only hope that Sigma continues to improve that lens line, and that Canon themselves decide to put out a comparable option.this
Yes, the IQ with the prime is slightly better - but in the era which both lenses are from, that was the norm (actually, it's still the norm, with the exception of the 70-200mm f/2.8L IS II, which is a zoom that actually bests primes in the same range, e.g. 200mm f/2.8L II).[/quote]
I have to point out a problem with comparing the c. 2008 70-200mm f/2.8 IS II to the c. 1996 200mm f/2.8 USM II design. The MTF charts on Canon's website
were a clue to me it's no new lens. (The dated looking product photo is another clue.) The intro of Photozone's article
clears up any mystery about introduction dates as well as the difference between the revisions (assuming it is accurate).
For a perhaps better comparison, take the 200mm f/2L IS
- despite being larger aperture still, it is nonetheless better corrected than the 70-200mm f/2.8L IS II zoom. The price points seem irrelevant to me - when Canon releases new designs they are generally the best available for the materials included. The older 200mm f/2.8 design, of course, is the only option available at that price point and that specific form factor - but they could do better today, especially with more advanced materials.
The "zooms today are better than primes" tale I've seen gaining traction especially since the 70-200mm f/2.8L IS II is a myth to me. I think the gap between primes and zooms is much smaller than before, and for functional photography almost nil...but the MTF charts don't lie, either. The maximum modulation transfer of a good recent prime design is far ahead of a good zoom, especially when you get further to the corners, although the critical difference found in many older zooms of wild differences in modulation transfer between meridional and saggital lines is much improved these days. Exotic materials in zooms don't negate the potential of primes to do better with fewer elements, lesser "correction"-induced abnormalities, and to do so at a lower price and often even with fewer exotic materials. And when you get into teleconverters, the near-flawless MTFs of newer primes will really start to prove their worth.