Canon R 300mm f/4

Decent lower priced alternative to the L glass It is a bit noisy when using the image stabilization, but it works as advertised. Paired with the 6D I consider it slow to focus. I am not trying to shoot sports or other very fast activities, so there's no real heartache about it, but it's worth noting. i used to own the non IS version of the 75-300, and I like the bit of latitude in low light situations that the IS offers. Decently sharp images even at 4.0. Good value.

Soft Image at Large Aperture The lens is not that good. At large aperture, the image is not sharp. You get want you paid for. Also the USM focus is very noise. I wish I had stayed with STM which might be cheaper too.

Not perfect, but GREAT lens for the money I bought the EF 70-300 f/4.0-5.6 IS USM zoom lens because I was looking for the extra length that my EF 28-135mm f/3.5-5.6 IS USM wasn't delivering for things like sports and wildlife and when subjects were out of reach. I had originally considered the EF 70-200mm f/4L USM lens but opted for the significantly less expensive 70-300mm lens because I had heard good reviews about the lens and decided to try and save some money in the process of expanding my opportunities. This lens has sharpness to be appreciated! When shooting wildlife (birds, squirrels, frogs, turtles, etc...) the extra reach is very handy and everything turns out very nicely. Neatly blurred backgrounds provide a good smooth canvas for clear subjects that really stand out. Image stabilizer system may be a tad noisy (noticeable, at least) but what it lacks in silence, it makes up for in competence as I was able to hand hold even slow shutter speeds of around 1/10th sec even at full 300mm zoom! There are, however, a few things I wish this lens did have that it does not. The front of the lens rotates during focus and extends when zooming, and the Micro-USM system does NOT allow full-time manual focus, and the lens lacks a distance scale. The more expensive L-series lens does have all these features, along with others I didn't bother listing, but lacks image stabilization. Finally, the lens does display some pincushion distortion, although, depending on how your shots are edited, you might never notice. There may be some things that this lens is not PERFECT for, but for the small bit it lacks, it easily makes up for. VERY NICE for the money!Read full review