Canon EF 300mm 4.0L IS

This is my second L series lens, and I've had the same problem with both of them, neither auto-focuses accurately on one of the 60 D bodies that I own. The problem may be with the one body, but all my other lenses, Canon or other brands, work well with that body.

I've had this lens for about 6 months now and I absolutely love it! Great buy! Even better price!

Puchased this lens a week to ten days ago. Best lens I own. The AF is quiet, IS works as it should, not as light as you'd think but, having it on a 1Dmk3 is worth its weight. functioing range is a bit short for birds unless your within 50 feet. Still searching for mtn. cats, bears, ect, but would expect to be within the capapbilities of the lens.

I have owned this lens for eight months and it, together with an EF 1.4x III, stay on my 5D Mark III more than 90% of the time. I absolutely love this lens, and picked it out to get a bit more reach over my EF 200 f/2.8L II (also a superb lens). The autofocus is fast, dead accurate, and the color and contrast are outstanding. With the teleconverter image quality is still excellent. I shoot wildlife, birds large and small, flying and still, turtles, dragonflies, and it handles them all superbly. The detail rendered by this lens is astonishing, and the bokeh is beautifully creamy as you would expect from a lens of this length. The image stabilization works also very well. For the price you can't beat this lens if you want fantastic quality in the 300-400mm range.

I bought this lens to shoot plays and sports events. It has been acceptable for sports but I cannot use during indoor plays due to the the loud IS. It is too distracting to people anywhere near me. I sent in to Canon service and they say that it "performs to factory specs". I plan on selling it.

I've owned three of these over the years looking for the lens some people say they have. These lenses have been a disappointment to me in terms of pure sharpness and contrast compared with my old EF 300 2.8L. When comparing price, handy size and weight the EF 300 4L IS USM is clearly a very desirable lens but for pure optical and focusing performance the old EF 300 2.8L clearly beats the EF 300 4L IS USM both on film (EOS 1N's and 1N-RS) and EOS 1D and EOS 1Ds bodies I had at the time of comparison.

I recently sold my 2011 300mm f4 IS lens after about six months of ownership. It was the perfect size and weight for a 300mm prime, and the short minimum focus distance was ideal for a variety of subjects. It had an excellent sliding lens hood and a nice soft case was supplied at no additional cost. I really wanted to like the 300mm f4, but at the end of the day image quality is all that really matters, and in this regard the lens was a disappointment for me. I use a 40D, and if I was careful to shoot stopped down to at least f5.6 this lens could produce pretty good images, but not significantly better than the 70-300 consumer (non-L) zoom stopped down to f8 that I used to own. I bought the 300mm f4 planning to use it with a 1.4x teleconverter, but this degraded the image noticeably, even stopped down to f8. In addition, the IS on the 300mm f4 was only good for one or two stops max with no tripod-sensing feature, and the AF was not consistently accurate and was too slow to follow birds in flight when using a 1.4x teleconverter. Downloading images at the end of a day shooting with the 300mm f4 was often frustrating – too many missed shots that were either slightly out of focus or simply too soft for my expectations.

This lens is amazing as a macro lens. I shoot with a Canon 100mm 2.8 macro also and love it, however I have to position too close to the subject To shoot macro with the 300mm, I have the ability to shoot from a little distance, and still get a fantastic shot. With the 300mm 2.8L, resuls are clear, crisp and he bokah is fantastic. Extension tubes are a must have to use this lens as a macro.

This lens is a real bargain. It is a serious professional lens, but since it has been in Canon's line-up for more than a decade, it can be bought for a really nice price. The AF is actually very quiet. Many people saying that AF is loud simply mistook the noise of the old IS system for the AF noise. Turn off IS and you get a quiet lens, although you will need a support and faster shutter speed to compensate.

i purchase this lens from canon website they ship it fast i receive it only 2 days after purchase. the auto focus is loud and eats battery but works very well im super happy.