Canon EF300/2.8L and 600/4L

At one time I owned both these lenses but a number of years ago I switched to the 500/4.5L and 300/4L for reasons of weight, not optical performance. Canon has now replaced both these lenses with IS (Image Stabilized) versions, but I'm briefly reviewing the non-IS lenses here because they are now much more affordable on the used lens market.

Both lenses are as sharp as a lens has a right to be, even wide open! Basically you can't argue with the construction or performance of either lens. Both are great with a 1.4x TC and still good (but not quite so great) with a 2x. They share the common features of this generation of Canon USM lenses, with 3 focusing speeds, full time manual focus (electronic), focus preset etc. Both take 48mm drop-in filters. There's really not much more to say on a technical level. These are very, very good, very, very sharp lenses. The best in their class.

So why did I sell them if they are so great? Well, for the 300/2.8L I found that the 300/4L was very nearly it's optical equivalent. Maybe you could tell the difference on an optical bench or shooting resolution test charts, but in the real world I'm not sure you could tell them apart on the basis of optical quality. The 2.8 is a stop faster of course and it will AF with a 2x TC on any EOS body. However now the 300/4 will AF with a 2x TC on the EOS 3 and 1v. The extra stop is very nice to have of course, but for me (and maybe not for you) the optical advantages didn't justify the extra 3lb in weight, increase in size and $3000 in cost of the 300/2.8L. I found that I'd often leave the f2.8 at home or in the car, while I'd carry the f4 with me. A lens in the car or at home isn't a useful lens! So I have nothing bad to say about the 300/2.8L. It's a great lens if it's what you need. It just wasn't what I needed.

I loved the 600/4L. It was a great lens, but it was BIG and it was HEAVY. One you actually got it to wherever you needed it and put it on a big tripod with a solid head it was capable of yielding stunning results, but it was SO BIG and HEAVY that it was a pain to haul around. It really is a lens that spends most of its time at home or in the car. It's not something I would carry around "just in case" I needed it. Now some people may be younger and stronger than I am and not be concerned about such matters. In that case, this may be the perfect lens for them. But it wasn't the lens for me. I swapped it for a 500/4.5L. The 500 is just as sharp, but 1/2 the size and weight. I lost 100mm in focal length and 1/3 stop in speed, but for me that was a fair trade for the size and weight reduction. The 500 will AF with a 1.4x TC on an EOS 3 or 1v, but is still MF with a 2x (1000mm f9). The 600/4 will AF on those bodies with a 2x (1200mm f8). It's another case where, for me, the optical advantages of the 600/4 didn't outweigh the extra size, weight and cost. For some people this wouldn't apply and this is a great lens for those people.