A LOT of lens and a LOT of satisfaction!

It is always hard to know where to start with lenses like this as I don't want to tell you just things you can work out from the title. So telling you it has a wide focal range is pointless, of course it does. The aperture range is decent for this range though you would be less likely to use this at the 100mm end if you have smaller lenses as they are likely to open wider. I have the Canon 100mm F2.8 lens (see my other reviews) and would always use that over this lens for short telephoto work without question.

Is this lens sharp? Of course it is. Why of course? Because it is a Canon L series so you can pretty much take that as a given. I have seen the odd review where they have said 400mm can be a bit soft but I cannot confirm that from my own experience. I have found it to be excellent throughout its range. of course it isn't as razor sharp as my 100mm prime lens but I can't imagine most people who are paying this sort of money for a lens would be expecting that. But it IS sharp and the definition is excellent. Contrast and colour saturation are spot on.

Yes this lens is pretty heavy but it is NOT so heavy that it is impossible to use without support from a tripod or monopod. I use a monopod most of the time and with the circular mount that is supplied with the lens it feels well balanced and under my control rather than being in control of me. It can be used hand-held but that is primarily down to the wonderful image stabilisation that this lens has. I can hand hold at 400mm and the images are amazing. When you first move to frame your subject you notice a bit of tremor, then the IS clicks into play and the effect is immediately obvious. The subject is held beautifully and it is says it all if I tell you I can use this lens on my 20D with a moving target at its 400mm end at 1/60th second and get an image I can sell!

The IS has two settings, one for moving images, one for static objects. When using a tripod you should not use the IS as the gyros will try and work despite the image being already stable and actually be counter productive. There is also a focal range limiter and lock so hunting for autofcous is reduced considerably.

This lens on a digital SLR has an equivalent focal length of 160mm - 640mm and you can still use the tele-convertors giving you up to double that though you will lose a fair bit of light with the 2x as it will be a max f11 at 400mm. That isn't a problem on a sunny day or with a tripod but let's be realistic, it is still a phenomenal tool for distance work.

The price is not cheap, you are looking at around the £1000 mark which is a whack on the wallet for most of us and in my case certainly had me hunting through my copy of '101 excuses for persuading your partner you haven't lost the plot'! But if you are even considering this lens you are not so much concerned with the outlay as with whether you will get the satisfaction this outlay deserves. The answer is a resounding yes, without question. Is there a choice? Yes there is. The Sigma 80-400mm lens is also very good. I can't say it is better or worse as I haven't used it other than seeing a few pics taken with it but I have chosen to keep my lens set Canon now and am appreciating the benefits in the results I am getting.

If you do a lot of photography which requires distance between you and the subject, eg sport, nature and wildlife, etc. then you will not beat this lens for this range. It is beautiful to use, the IS gives you as much as 3 stops advantage, the USM is typically fast and near silent, its weight is heavy but not too heavy and its build and optical quality is what you would expect from any L series lens.