Like I say, Ray, you've got to look sideways. My Olympus 50-200 on my E3 covers exactly the range of your Canon lens on a 5D (and with the dedicated 1..4 converter near enough to the range on a crop sensor Canon). It's sharp wide open and gives the same depth of field at f4 that your lens does at f8 on a 5D. It's also way lighter, cheaper and waterproof and focus is quick and accurate, even in the poor light that you photograph in. Plus, that big Canon zoom sucks in dust, not a problem at all with the Olympus setup. Olympus even make a 90-250 (=180-500 on 35mm) which is f2.8 all the way and also weather proof and sharp wide open. This is just one example of keeping an open mind.
Don't forget that Sony is bringing out the 70-400/4-5.6G, which should weigh about the same as the Canon but could well be sharper and is more useful. Or you could get the astounding 70-200/2.8G and stick a doubler on it and probably still match your Canon at 5.6. Also, photos I've seen taken with the 16-35 Zeiss are very promising indeed and that is a much more useful zoom range than the Nikon 12-24, just less trendy. If you have a 24" printer and Minolta lenses, the A900 must be your best option and does not cut you out of lens options at all. In fact, it gives you some awesome options you do not get with other brands, especially if you want your Zeiss glass to come in autofocus.
Gotta give up on you. You've contradicted yourself since the start of this thread and seem quite negative for no good reason. Let's hope you sort things out over the next few months and can get back to being happy behind your camera!
P.S. I recently tried out a Canon 400/2.8 on a 1DIII. Do you think I could get that thing to focus? A huge, huge setup, needing a monopod to hold it up and just a pig to use. I really had to wonder what all the hype was about and have to agree with you that it is not a serious option for photographing moving birds!
Deep,
I've been looking sideways for many years and have engaged in many debates on this forum about the merits of the 4/3rds system compared with APS-C and full frame 35mm. If you think the Olympus 50-200 on the E3 can produce better results than a Canon 100-400 on a 50D or 1Ds3 (in place of the 5D2), then show me some test comparisons. I've never seen any.
Not only have I never, never, never, ever seen any direct, controlled comparisons between the Oly 50-200 and the Canon 100-400 with the latest camera bodies, I can find no rational reason to
expect any improved image quality from the 50-200, compared with the 100-400 with larger format sensors.
No reason to
expect any 'significant' improvement
plus no pictorial evidence
demonstrating any improvement is not entirely conclusive I know, but is fairly and reasonably conclusive by my standards.
Let's consider what I believe to be the facts, rightly or wrongly. (Correct me if I'm wrong.)
(1) Zuiko lenses are generally sharper than their Canon counterparts
because they have to be in order to deliver the
same resolution, due to the greater resolution demands of the smaller 4/3rds sensor.
(2) Out-of-camera jpegs from the E-3 appear to be sharper than jpegs from the Canon 40D, leading some people on this forum to claim that the E-3 produces sharper (or better quality) images than (even) the 5D. After the Dpreview tests of the E-3 we now know that RAW E-3 images are actually slightly
less sharp than 40D RAW images, due to the stronger AA filter on the E-3. I would think a 50D would widen that gap.
(3) There is clear evidence in both the Dpreview and Imaging Resource tests that the 40D has lower noise and produces sharper images at high ISO than the E-3. There is other evidence elsewhere, and my own tests also confirm this, that the 5D has a significant high-ISO noise advantage over the 40D and 50D.
(4) Whilst it's true that smaller formats have a DoF advantage when used at the same aperture (comparing equal FoV images) this advantage appears to be completely wiped out by the lower noise and potentially better image quality of the larger sensor with its greater light-gathering capacity.
This is how the relationship works. Comparing the E-3's 17.3x13mm sensor with the 40D's 22.2x14.8mm sensor, we find that the E-3 has a DoF advantage of 1/3rd to 2/3rds of a stop depending on whether we're cropping the E-3 image to 35mm aspect ratio or cropping the 35mm aspect ratio to a 4/3rds aspect ratio.
However, the 40D has at least a one stop noise/image quality advantage over the E-3. If we were to pixel-peep comparisons betwee the E-3 at ISO 200 and F5.6, and the 40D or 50D at ISO 320 with lens at either F6.3 or 7.1 depending on cropping, we might find the 40D or 50D would still have the edge. But either way, it's merely a pixel-peeping edge we're talking about. I'm after something more substantial.
(5) Whilst I would not be surprised if the the Oly 50-200 were sharper at F4 than the Canon 100-400 at F5.6, a 1.4x converter will not get you even close to the FL of a 400mm lens on the 50D. You need a 2x converter.
Converters always downgrade lens performance. It's unavoidable. A 2x extender also converts that maximum aperture of F4 into F8. I can't see any hope of improvement with this suggestion of yours, but thanks for trying
Olympus even make a 90-250 (=180-500 on 35mm) which is f2.8 all the way and also weather proof and sharp wide open. This is just one example of keeping an open mind.
This option looks more promising. However, that lens would still need a 1.4x extender to match the 640mm equivalence of a 400mm lens on the 50D. With 1.4x extender, 250mm at F2.8 becomes a downgraded 350mm at F4. Factor in the small crop factor in relation to the 50D and you get something like 400mm, so the effective FL is roughly equivalent. But I'm very doubtful that a downgraded zoom lens at F4 and ISO 200 (for example) on the E-3 would exceed the quality of the 100-400 at F5.6 and ISO 400 on the 50D.
But thanks for your help. If there are any comparison images out there addressing this specific issue, I'd be very interested.