70-200 2.8II vs. f4 IS bokeh comparison? Or a visual bokeh comparison tool?

[Legion5]

The Bokeh of the F/2.8 IS II is somewhat noticeably worse, especially in the transition areas. I don't know why you assume it would be better. In fact the F/4.0 IS is overall better in every single way except CA (CA is almost nonexistent in both) and vignette, although I've tested several copies back to back with the F/2.8 IS II and they trade off in resolution with the overall victory going to the F/4.0 more often but because they are so close that sample variation is the biggest determinant of quality.


Personally on a full frame body I believe the F/2.8 IS II isn't a very useful lens, F/4.0 at those focal lengths is already barely usable for me, and my preferred combination is 24-70 F2.8 and 70-200mm F/4.0. The main advantage I see to the F2.8 IS is with teleconverters, which due to aperture speed is will be limited with the F/4.0 IS. I've seen over 160 lenes and the 70-200mm F4 IS is as close to perfect as it gets, it's only flaws are vignette, apochromatic performance, and focus breathing, you couldn't ask for more in this day and age.

[darklord]

Personally on a full frame body I believe the F/2.8 IS II isn't a very useful lens, F/4.0 at those focal lengths is already barely usable for me,
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Could you please elaborate what do you mean bythe f/2.8 is not very useful on a FF body and the f/4.0 is barely usable?

[Legion5]

As btaylor said f/4.0 is an very narrow DOF and is often capable of cutting someone's body or face in half when taking up most of the frame, f/2.8 is even narrower.

[neuroanatomist]

As btaylor said f/4.0 is an very narrow DOF and is often capable of cutting someone's body or face in half when taking up most of the frame, f/2.8 is even narrower.

Yes, the DoF is thin. But, if you compare the DoF at 200mm f/2.8 with a similarly-framed shot at 85mm f/1.2 (closer to the subject, obviously), the DoF at 85mm f/1.2 is less than half of that at 200mm f/2.8. The EF 85mm f/1.2L II is Canon's quintessential portrait lens. Granted, not all portraits are shot at f/1.2. But sometimes, that's the effect you want...and while you can stop down the 70-200mm f/2.8 for more DoF, you cannot open up the 70-200mm f/4 any wider than f/4 if you want the DoF to be shallower.

[canoli]

you cannot open up the 70-200mm f/4 any wider than f/4 if you want the DoF to be shallower.

well you could but you'd need a good drill press and a hole saw... however, be forewarned this procedure would likely void your warranty!