Hi Malcolm,
where are these "most reports" that say the prime is better then the zoom?
(I know you're not "taking a position" here - but you raise an interesting point, hence this).
True, Daniella and Gene ("Hawkman") on DPR will shout
anybody down who dares disagree with their opinion of the prime, but
Art Morris knows a thing or two about image quality, and he has stopped using his prime in favour of the zoom, because its versatility gives him shots the prime can't, without any of the supposed IQ trade-off. He says:
Art Morris said:
Confession #1: Though I still consider it the best lens in the world for photographing birds in flight (see FAQs on web site for details), I no longer carry my beloved "toy lens" - the Canon 400mm f/5.6 L - on my shoulder as my auxiliary intermediate telephoto.
It has been replaced by the Canon 100-400mm f/4.5-5.6L Image Stabilizer zoom lens. I have been using the 1-4 more and more every day and - contrary to some reports from other users - have been making razor sharp images at all focal lengths with wide open to moderately stopped down apertures.
In addition, I have it used it wide open, handheld with the 1.4X tele-converter with excellent results (with static subjects) at 560mm.
For bird photography, the versatility of this lens is unmatched; I find myself making images that I would never even have thought of before - especially of groups of birds in their surroundings.
And though it is heavier than the 400 f/5.6L, it is also a superb flight lens.
At Bosque Del Apache NWR late this fall, I used the 1-4 on a tripod before sunrise for "bird-scapes" and then again almost exclusively for the spectacular blast-offs.
I only wish that the zoom were a bit smoother.
I am even considering selling one of my 400 f/5.6s; I never ever thought that I'd say that when the 1-4 first came out.....
Both the zoom and prime can give
excellent real world image quality, and "better" in the eye of the beholder anyway - as I'm sure you'd agree.
There are as many people who consider the zoom to be better than the prime, because possible, theoretical, maybe-there-maybe-not sharpness benefits attributed to the prime are trivial to non-existent in any test I've seen between the two (maybe the prime is better wide open, but there's bugger all in it), but the zoom with its IS and shorter focussing will
do a lot more, and it's usually the user that makes the biggest difference.
A quick look in the gallery here will show up any number of pictures from the zoom which are sharper than pictures from the prime.
You'll see people explain this by saying "ah, but that's because the prime doesn't have IS" - which is as much of an admission as you need that the zoom,
as a package, can indeed produce sharper images in real world situations than the prime can.
Of course, some people might have a sub-standard version of a given lens, but my own suspicion is that when you see iffy shots taken with the zoom, it's because users think that IS is a miracle cure and have therefore done nothing to develop a decent hand-holding technique, assuming that the lens will do all the hard work: it won't.
Users of the prime don't have any such expectations, and so probably try harder!
