I use this lens to shoot motocycle motocross racing, indoors and outdoors. Just this one lens covers most all situations, and eliminates the need to carry a second camera and lens. It's a bit heavy, and hard to loosen to zoom, but well worth the investment. When Mark III and the lens hit it, the images are awsome.
I am a professional. I shoot NFL, NHL, MLB NCAA and news as well. I REALLY wanted this lens to work. I used it on a new 7D. I tried night football, hockey and indoor basketball. All network television lighting. I was surprised that it worked out well in football and at hockey the Overall diameter was small enough to get through a whole in the glass (unlike a 300 f2.8) However, the shortcomings at basketball were far too great. It is just too slow at 5.6 to be useful. I had to shoot at 5000 iso and NOISE, NOISE NOISE! Besides that, at a close participant/spectator venue like basketball, the DOF is too great. (depth of field) When shooting the other basket, the fans behind the players were sharp enough to be visually distracting. Similar issues with players on the bench behind the action. Also, the mechanics of the push pull zoom weren't user friendly for my needs. Between say 200 to 300, its very stiff and is a very small adjustment. The location and methodology of the locking zoom ring is a bad design. It takes two hands to lock or unlock. If you don't lock it in short, the lens slides all the way out to 300 and is very awkward. If this lens were half the price, or fixed at 3.5, I would buy it despite those shortcomings. Now others have said it's too big and heavy. I thought it was rather compact for what it is. It's only a few ounces heavier than the 70-200 2.8 and not much longer. If you were to replace that 70-200/ 2.8 around your neck with this, you'd hardly notice the difference. Except when the lens extends itself.
I´m a stock photography shooter and I live out what my agencies is paying me monthly. I decided to buy this lens to reduce the number of them that I have to carry along when traveling around the world, but I abandoned it a bit because its weight,;however is a must lens for aerial photography. Now is the only lens that I carry on board of any Cessna or helicopter that hire to shoot stock. Beautiful focal lens range for the altitudes that I need in this kind of work and drastically reduces the amount of stuff that I need to bring on board where the space is scarce.
Pros: Super-sharp images, Superior build quality, Fast auto-focus, saves carrying extra lenses
Cons: needs to be used to the way you zoom in and out
This lens has performed well for the two years it's been in service. Very functional except in low light. Very versatile range.
The only complaint is the same as with all auto focus lenses, no quick pic when the lens/camera has trouble distinguishing a focal point. The telephoto tubes had a problem with the friction ring, which tightens the lens down at various distances. Once that goes, the lens slides out to the full 300MM focal length making it useless for any tilt angle tripod work.
I recently purchased the 5D Mark II and this lens with the sole purpose of making video. This lens has surpassed everything I had hoped it could do and has produced the sharpest video footage ever. As another person reviewing this lens had pointed out, you do need to turn OFF the image stabilizer when shooting video to get sharper footage. This is true. The versatility of the lens allows one to be extremely creative and you don't need to change lenses to get the effects you need. This lens is the perfect lens for the 5D Mark II camera, and makes shooting video so easy. Very solidly built. Heavy, but I like that because I feel as if I'm getting my money's worth. Even the still images were pin sharp. Finally I have a lens that produces the sharpest video and I sincerely believe that the 5D Mark II and the EF28-300mm f3.5-5,6L USM are a match made in heaven.
Pros: Super-sharp images, Superior build quality, Fast auto-focus, best lens for shooting video with the 5d mark ll
Many of my fellow enthusiasts have the 100-400mm lens. I bought this lens before I knew what most others have. And I'm glad I did! This lens works perfectly with my 30D and my 5D Mark II. Especially on the 5D Mark II. This lens give you the best of both worlds. Wide angle and telephoto! I've had this lens for almost 3 yrs now and I wouldn't do without it. I now know the sweet spot is f/7.1 for the sharpest pictures this lens will give. Otherwise you do get a little softer focus with this lens but the versatility of this lens makes my other photography friends jealous. I have a super wide angle zoom and this lens and that's it! With my 5D Mark II and it's 21.1 MP it's like almost having a macro! I can't do without it. enough said.
Pros: Super-sharp images, Superior build quality, Fast auto-focus, still fast enough for those birds in flight!