That would be a major disappointment! A big part of the attractiveness of a 2.8 telezoom is to be extendable. Anyway that was a fixed consideration / the planned next investment step for my 70-200.I'm not convinced that they won't be compatible. It's possible the statement above is just to associate the new TCs with the new glass.
We need the formal release document that flags what is / is not compatible. No ability to TC a 70-200 would be a hell of a takeaway for the EF faithful, wouldn't it?
I love the 2x option on my EF 70-200 f/2.8L IS II. It effectively killed off the need to get a 100-400 L II (given how infrequently I shoot longer than 200mm).
There are some disadvantages beyond simple cost. For instance, I personally take photos of wildlife and, to a lesser extent, landscapes. I often go on long hikes with lots of climbing, which sometimes means making a tough choice regarding which of my lenses to bring with me for the day if I can't bring them all. Back in the olden days (pre-COVID), when travel was allowed, I also brought my equipment on small planes with (ridiculously) small size and weight luggage allowances (thank goodness for travel photo vests with large pockets ).
When having to make choices regarding which equipment to bring, a 70-200 with TCs is a very strong contender against a 100-400 or 100-500, as the ability to not use the TCs opens up the benefits for low light and shallow DOF, and the ability to use them helps with reach when needed (which is often). Not having that TC option makes the applications of the two lenses completely different, meaning you are more likely to "need" both. Totally fine when size and weight (and money) are not an issue, but arguably a major drawback for those of us who are carrying gear around for hours on end and who are sick of arguing with airport check in staff about why we refuse to put items made of glass in our checked luggage.
Yeah, it leaves the door open for the RF 70-200 to work with the TC's, but I'm done speculating. Just wait til Thursday when all will be set in stone. I kinda went on a rollercoaster hoping to use TC's with the RF 70-200, then seeing the initial leaked images which ruled out that configuration. That got me lusting for the 100-500. Then we get a rumor saying they will work with all lenses which got my hopes up again. Now I'm back to mentally preparing myself to save up for the 100-500.Technically, the TCs could be used on the 70-300L but only at the longer focal lengths. I tried it for the novelty of it, but it's not a good solution worrying about marking/damaging the rear element of the lens.
I think it goes without saying it wouldn't be as good. It's for those who don't have the budget or want to spend another ~$3K, but would like to have extra reach.
Anyone else notice that the installed lengths of the RF TCs are shorter than the EF TCs? RF 2x TC saves about 1 cm, and RF 1.4x saves about 0.5 cm.... Not huge, but welcome. Too bad the weight didn't decrease...
I am curious as to why the 2x is being released now. Does Canon really expect people to use it with the 100-500 or the f/11 lenses? Wouldn't it have made more sense to release the TCs with the supertelephoto primes?
Yeah, but then it would have made sense to release the 5-series-level body with the pro lenses last year too, no?
I think often the release timing has more to do when things are ready with Canon of late. I doubt there is a business school professor somewhere using Canon's release schedule as a case study in exemplary system roll-out.
Great is always subjective .. as others indicated, sometimes when you travel and space is an issue 70-200 + TC is a better option than two large lenses. Correct the quality isn't same, but getting a shot is better than not at all because you left you other lens at home. This was a decent example with 70-200 2.8 v1 and 1.4x tc v1. Had to downsample to upload here. This is 280mm on a Canon 80D (so also 1.6x)