On my DSLRs I have the "Set" button assigned to ISO. While pressing and holding it with my right thumb I can change the ISO with the main dial just behind the shutter button using my index finger.
One reason I decided to not use the ring on the Rf lenses is because I plan to continue using my 5D IV for another couple of years, at least until Canon releases a more versatile FF mirrorless. I've already made the choice to accept muscle-memory confusion going back and for the between the 5DIV and the EOS R, to just roll with it. But I see absolutely no reason I should make it worse by having some functions on my lenses when they are on the R but not the 5DIV.
To put it another way, not using the control ring on the lens has made the transition to the R easier, and it makes using the same EF lens on both the R and the 5DIV much simpler. For me.
Regarding these price drops...Wow. Still very tempting to sell off my venerable old 5DIII and replace it with another 5DIV. That was the plan before I took a walk on the wild side and bought the R, a great decision, as my portraits are better than ever using it. However, for me, the R is now a specialty camera, strictly for portraits. (Sure, I could use it for landscapes, but the 5DIV is just as good with LiveView, and it has better weather sealing--and it can catch the unexpected bird-in-flight or other action opportunity.)
I truly understand the frustration of event and wedding photogaphers who don't believe the R would work for them. The EVF not only "loses" track of a subject that moves just a little too quickly, but it takes getting used to in other ways. For example, while you can see your exposure before taking the shot, very often, pressing the shutter button halfway down brightens the image in the EVF so it looks likes overexposure. It's quick, and the actual exposure of the image is not affected, but it is another example of how, in my opinion, this EVF simply isn't ready for prime-time use other than for static to leisurely or predictably moving subjects.
I wouldn't get a tremendous amount for the 5DIII, but it is not going to see any real use at this point. And my oldest kid won't be able to handle a FF camera for another four years or so. I think I'll sell it (camera, not kid) and wait and see: Maybe the 5DIV will come down even more. About two months ago Amazon just decided to drop the price to $2299 for about five days. Oh, I almost pulled the trigger, but couldn't resist the lure of the R and its primes.
Should I just be satisfied with the 5DIV and the R as a working team right now for portraits, frequent events and the occasional wedding? I guess I'll try for a while and see how it goes. The R would be for details and portraits, the 5DIV for all else. But any action or threat of light rain, the R, to me, is problematic.
What a great time to be a photographer! So many great cameras and lenses! So hard to go wrong if the intention is to take great pictures!
