Luminous Landscape Forum

Equipment & Techniques => Mirrorless Cameras => Topic started by: phila on December 10, 2019, 04:32:25 am

Title: Canon RF 70-200F2.8L IS teardown
Post by: phila on December 10, 2019, 04:32:25 am

Makes for an interesting read (especially if you used to be a Canon technician as I used to be several decades ago). Canon has obviously very much raised the game with their RF L lenses.

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

Title: Re: Canon RF 70-200F2.8L IS teardown
Post by: Christopher on December 11, 2019, 03:31:10 pm

Looks like a really nice lens inside. Haven’t sent anything that nicely designed.

Title: Canon RF 70-200F2.8L IS (not USM!) teardown
Post by: BJL on December 12, 2019, 12:08:20 pm

Thanks for the link.

Some side points interest me:

- Even with a longish minimum focal length of 70mm (far deep than Canon EF mount) there is benefit in having large rear elements so close to the focal plane that the design would not be possible for an SLR — and maybe not for Sony's narrower E mount.

- The plug for the superiority of suitable polymers (like polycarbonate) over metal in most places.

- The use of a linear focusing motor rather than ring style (USM in Canon jargon). Canon has been saying the linear motors ("STM") have some advantages for smaller lenses but that USM is still the best for high performance; now it seems to be moving on from that.

Three ways in which traditional thinking and approaches are abandoned.


P. S. Doesn't this thread belong in the sub-forum "Cameras, LENSES and Shooting Gear"?

Title: Re: Canon RF 70-200F2.8L IS teardown
Post by: phila on December 13, 2019, 03:40:24 am

I figured given it is a lens for mirrorless...