f/2 and f/2.8 are pretty close, f/2.8 and f/4 are different. All those samples are taken with the same lens. IMO, the bokeh of the 70-200 f4 IS is more consistent than the 70-200mm f2.8 IS. It all depends upon the frequency of the background pattern, how far away it is in relation to the camera and subject and what f-stop is set. However, if you are going to hand-hold the 70-200, I would definitely recommend IS! One other lens to consider is the f/4 L IS MkII variant that is much lighter 730g vs. 1.48kg (worth thinking about as we mature). It came out about the same time as the f/2.8 MkIII and is a beautiful lens. It was not produced for that a long time as it came late Lens hood is reversible. Canon EF 70-300 F4-5.6 IS II USM. Canon RF 70-200mm f/2.8L IS USM. The lens hood can screw onto the lens in reverse so that you can keep it on your camera at all times, ready to use. filter size. 67mm. 77mm. This measurement is important to take into account when buying filters. Therefore, the 50-140/f2.8 is equivalent to the Canon 70-200/f4 when talking about speed (light gathering) only. You used "light gathering" in both sentences. I think one sentence must be false? perhaps you should use a different term. hint. Think water. There is a difference between current and flow rate. alexne wrote: In fact, it seems that the f/4 IS lens wide open at f/4 is the same as the Canon 70-200mm f/2.8L IS stopped down a stop to f/4, and the f/4 lens is better than the f/2.8 lens with them both at f/5.6. This is another good reason not to want to haul the huge f/2.8 version around; this smaller one has the same performance at any given aperture so Instead, I’d get the awesome Sigma 18-35 f/1.8 lens to cover your wide end shooting, and then get a 70-200 f/2.8 for your telephoto, and if you feel like you’re missing something in the middle of that 35-70 range, you could always pick up a 50mm prime, or instead of going with the Sigma 18-35, get a 17-50 f/2.8 (Sigma) or 17-55 f/2.8 (Canon). Switched from Canon 5D series to Sony a7 series but kept my Canon 70-200 f/4 IS. Even with a Metabones IV adapter, I got a lot of out-of-focus shots of a rapidly moving small child. Sold the Canon and bought the Sony f/4 70-200 and eliminated the problem. I can't say which lens is shaper -- it's hard to compare zooms. I am trying decide between purchasing the Canon 200mm f/2.8 or the Canon 70-200 f4 IS, based estrictly on image quality : resolution, image color, contrast and sharpness. (I disregarded the other options in the Canon lenses line-up because I find them too heavy, including the ligther 300mm f/4 IS). YCrDw.