[thxbb12]

Roger Cicala's teardown of the Canon RF 70-200mm f/2.8 IS lens.

https://www.lensrentals.com/blog/2019/12/the-not-very-long-awaited-teardown-of-the-canon-rf-70-200mm-f2-8-is/

If you don't want to read the whole article, just read the last section "Conclusions and Impressions".
Very impressive indeed.

I particularly like what he says about metal vs plastic:

"There are some of you who are going to scream about how you want metal lenses. OK, Boomer, go get you a metal lens and show us how strong you are. On every other 70-200mm lenses we’ve disassembled, there are multiple metal parts that we can bend with our fingers. There’s not a damn thing we can bend with our fingers in this bad boy. This is going to hold up better than a metal lens, it’s probably sturdier, and it weighs far less."

[Brightcolours]

Oh bleah. Serious talk about the advantage of the wide mount. Some won't like that and will file it under "ignore the facts".

[Spinifex]

It seems like a very nice lens indeed... but I doubt I'll ever handle one, let alone buy one! It's simply not in the budget I'm willing to pay for such a lens. I'll wait for Canon's f4 version, or Tamron's 70-180 mm f2.8 when it is ported to the RF mount.

[JJ_SO]

Hahahahaha, that's outstanding, Canon manages to frontfocus a mirrorless lens.

Hilarious.

https://www.dpreview.com/news/6137048375/canon-users-report-issues-with-front-focusing-with-new-rf-70-200mm-f-2-8

Wonder how that happens?

[MatjazO]

Hahahahaha, that's outstanding, Canon manages to frontfocus a mirrorless lens.
...
Wonder how that happens?

Probably they can sort it out with FW. It does make me curious why it happens, is it related to sensor phase detect AF? I reckon it would not happen with contrast detect AF. Or?

[Brightcolours]

With DSLR PDAF, the sensors do not look at all colours and so they can get fooled with a certain part of the spectrum is in focus while the whole image is not. Not sure how colour blind PD AF implementations on imaging sensors are?

[JJ_SO]

With DSLR PDAF, the sensors do not look at all colours and so they can get fooled with a certain part of the spectrum is in focus while the whole image is not. Not sure how colour blind PD AF implementations on imaging sensors are?

Me neither. At least now I learnt for what the AF-adjustment of the Z might be good for - if one day Nikon brings out a lens with front or back focus issues I could correct it. I always wondered about that part in the menu.

[Brightcolours]

I wonder if it is about IR light in the case shown.

[MatjazO]

My understanding is that OSPDAF systems started as hybrid implementation. That is, they worked as combination of PDAF and CDAF. PDAF used for initial distance determination and therefore moving focus close to exact position. CDAF then doing final step(s). In that case, color information should be available. And focus should be accurate.

I wonder what has changed in latest implementations: Sony, Canon’s dual pixel as well as other have improved significantly. Do today (at least some) systems use PDAF only? Light sensitivity and accuracy were an issue of OSPDAF, maybe less so nowadays. In that case, wavelenght could be the reason for missfocus.

[Brightcolours]

Canon is going to bring a firmware update for this lens to fix the MFD focus issue.