Canon EF 70-200 f2.8 l iii vs 70-200 f4 l ii (which takes sharper images?)

RCicala wrote:

ZX11 wrote:

John Crowe wrote:

They will be virtually the same. So, do you prefer the far lighter weight of the f4, or the slightly better subject isolation, and slightly better low light of the f2.8?

f2.8 was fine for shooting my kids' soccer for 2 hours a day, but when it meant standing and panning race cars/bikes/snowmobiles for half a day, I switched to f4. I have never looked back.

You won't likely even see any difference with the non-IS versions either.

Non IS were not as sharp for some reason Half the reason to upgrade to the IS versions was because of IQ

Of course, difference in actual use may be greater than tested (when IS is helpful) or less than tested (depending on field conditions, etc.) but from a purely resolutions standpoint:

The original non-IS f/4 was better than the IS v1; this was the early days of IS and it was felt the addition of IS was worth a slight drop in IQ. The f/4 IS II is significantly better optically than either.

The f/2.8 non-IS and IS 1 are pretty similar, although the non is slightly better (probably within the range of sample variation). The IS II was better than either; the IS III is optically exactly the same as the IS II.

One thing to consider if you're buying a used one is the older lenses are generally no longer repairable; there aren't parts.

Again, this is bench testing. Bench testing is kind of "if you are in perfect conditions in the field you'll see this". Reality is you usually aren't in perfect conditions in the field and they're all pretty good lenses so you might never notice the difference.

Was there ever a non IS f2.8 version 2 or version 3?

The reviewers were likely reviewing the versions available in 2019.  The non-IS was cheap enough but the IS version at the time (mkII?) had too many advantages beyond just the IS.

I bought IS version 3 because the version 2 was no longer in the local camera store.  They let me try it on my EOS R in the store and I liked it.  Interestingly, they no longer let people put the lens on their body due to people maintaining eye contact with the sales person while walking out the store with it.  Nothing they can do with those thefts.  Sad times.