I've had this lens for 4 years now and it never failed once. The build quality is superb, it's been putting up with my heavy duty use and is working as good as new!! I've even dropped it on the floor once and it was fine!!I find this an excellent lens for birds and other wildlife photography.
I was also concerned about the push pull design sucking in dust but the problem never came. The push pull design makes it a very compact lens.
It is sharp all round, though I do notice a slight decrease in sharpness at 400mm f/5.6, but you will only notice when you view at 100%.
The AF is very good, accurate and pretty quick with both 20D & 50D I had.
IS is very good despite of the lock ups which occurs rarely. With a bit of practice, taking a photo at 1/30th handheld will not be a problem.
If you are looking for a flexible lens built to last, this is the lens for you!!
I was also concerned about the push pull design sucking in dust but the problem never came. The push pull design makes it a very compact lens.
It is sharp all round, though I do notice a slight decrease in sharpness at 400mm f/5.6, but you will only notice when you view at 100%.
The AF is very good, accurate and pretty quick with both 20D & 50D I had.
IS is very good despite of the lock ups which occurs rarely. With a bit of practice, taking a photo at 1/30th handheld will not be a problem.
If you are looking for a flexible lens built to last, this is the lens for you!!