[Klaus]

Quite an awesome lens ...

https://www.opticallimits.com/canon_eos_...rf70200f28

[Brightcolours]

I think the widening focus breathing should be worth a mention.

The header for the sample images part reads "Vignetting".

I also think that the worry for dust due to the extending construction should not be there, lens rentals showed the impressive sealing measures. And non-extending 70-200 lenses pump air around while focussing too, so also can show dust inside after use.

[Klaus]

Is focus breathing really a big thing?

I added a sentence about it.

[you2]

Correct me if i am mistaken but isn't the LoCA rather low for f2.8 200mm conversely isn't the vignetting unusually high at 200f2.8 for a tele zoom ? RSA seems high but if that is the cost for reduced LoCA perhaps a good compromise ?

[mst]

I also think that the worry for dust due to the extending construction should not be there, lens rentals showed the impressive sealing measures. And non-extending 70-200 lenses pump air around while focussing too, so also can show dust inside after use.

"Impressive sealing" does not help against one very basic fact: any lens that changes its length, pumps air in and out (unlike non-extending lenses). That is not possible without occasionally pumping small particles in and out, too.

Any extending lens design I know will collect some dust over the years. Some to a lesser extent, some very visibly (the 100-400 L IS for example is notorious for accumulating dust behind the front lens group).

From my experience: any extending zoom lens, that has been used (and not been sitting on a shelf) will show some dust inside. If you can't see any, you simply haven't looked hard enough

[Brightcolours]

This is what mr. Cicala writes:

"And a new thing we hadn’t seen before. The ports under the filter ring are covered with a breathable filter. This would let air pass through as needed but would filter out dust particles. Nicely done."

So, I maintain what I said above. Non-extending lenses do move AF groups which WILL push/pull air, and which WILL get dust in at some point. This extended lens has a special seal that lets air through, but no dust particles.

[mst]

Well, ok... let's see how this works in practice, I have doubts, to be honest.

Regarding non-extending lenses, I do disagree with your statement. Moving the inner lens groups moves air around, but only air that is in the lens already. So, in theory, there should not be any dust.

Practice shows: there is. But a lot less than in extending zooms.

[toni-a]

Dunno about service in Europe, but here it should be a no issue, all lenses will need some maintenance over time, like camera shutter aperture and flex cables have a lifespan so I would be more worried about those, besides any lens with frequent use, will need re-centering, cleaning is usually done for free with those services so I wouldn't worry too much, anyway depending on complexity of design elements cleaning at professional service isn't that expensive. I paid 30$ for for 17-55f2.8 IS, 20$ for 100mmf2.8 macro.

[Rover]

Wow. That was quick.

The prices are quite something though...

[Brightcolours]

Is focus breathing really a big thing?

I added a sentence about it.

In photography, only for those who look for a narrow FOV at close focus (and for video, the both the widening and narrowing kind can be intrusive).

So for me, this widening focus breathing is a negative for this lens. It could not replace my 70-200mm f4 L, which narrows its FOV, for a lot of things I do with it (or I'd have to add a lot of extension tubing).