I spent a good while pondering whether I could justify the expense of this lens, at around 6500.00 it carries a hefty price tag, but I finally took the plunge and demolished my bank balance. Just like any dream item on ones shopping list it could be argued that owning such a lens is more about ego than good reason, I am sure that there are a good few of them around the world that never get used to their full potential.
Along with its sister 500mm IS this is one of the big white lenses that is seen at all sporting events, look out at the football and motor racing on TV and these will stand out like sore thumbs in the photographers enclosures, when you see the results it produces there is no question as to why!
This lens has become a permanent fixture on my EOS 1Ds it delivers and some, the auto focus is instantaneous and has a full time manual over ride meaning that you can use AF and tweak focus to the most critical part of the subject, (usually the eye on birds). The wide f4 aperture has very shallow depth of field meaning that you can see it crack in and out of focus without any problem, there are few times when you will want to shoot at full aperture though, but even when using auto focus only, the clarity of viewfinder image means that you can hit the shutter confident of bitingly sharp results. Stopped down to the f8-f16 range this lens just cannot be rivalled, it is so sharp it will make you eyes bleed!
Image stabilising has two modes, and there is also a focus limiting switch covering three ranges, this is invaluable if your subject is at a set distance as it prevents the AF from hunting through its full range in low light, I use it when photographing highly mobile subjects like feeding waders, or birds at my feeding station.
Also there is a focus preset, very useful, recently when photographing a Kingfisher that uses the same perch on each visit, I preset focus on the perch, I could then carry on photographing other subjects, as soon as the Kingfisher arrived I activated the preset and there it was, spot-on sharp in the frame, without any wait, making the shot easy to get!
It is a big heavy lump of glass, do not expect to get to grips with it straight off, even with IS it is possible to get camera shake until you get used to using it, that said, once you have worked with it for a short while no other lens of this focal length will give such good results.
I have actually managed to get pin sharp flight shots with it whilst hand holding, in reality though you would do well to use beanbag or a good gimballed tripod head such as a Wimberley to get consistently sharp results. You will of course need a very substantial tripod, as it will weigh-in at an arm straining 8 kilos (17.5 pounds) with a camera attached.
When used on the 1Ds you can get AF with all 45 focus points even when using a 1.4X converter, but the system defaults to just the central focus point with the 2X, however I prefer to focus manually with the 2X as I have found that focus accuracy can very occasionally be slightly forward of the subject in lower lighting.
There is a drop-in filter drawer at the rear of the lens, which is also very useful, I fear though that this could be a weak point in the barrel of the lens that could break if the lens is badly handled or if it falls from an unsuitable tripod.
This is the lens of lenses, I have never before had such astonishingly crisp images, I think it could be that I will never have to buy another super tele, but I am sure Canon will at some point do even better, it will be a very tough job.
