Here is the Canon Cinema EOS C70

Can someone explain why a speedbooster works as an adapter between a full-frame lens and a full-frame mount? I would expect EF to adapt to RF without glass in between, just like on the EOS R series.

It is between ff lens and crop sensor. You get 1 stop of light more. Thats why it is called speedbooster.
 
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bbasiaga

Canon Shooter
Nov 15, 2011
721
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Can someone explain why a speedbooster works as an adapter between a full-frame lens and a full-frame mount? I would expect EF to adapt to RF without glass in between, just like on the EOS R series.
You don't need the speed booster. You can use the regular one too. You'll just get the normal crop on the field of view you'd expect when using a FF lens on a crop body. The speedboster is just another option to widen that out back to the 'normal' FOV of the lens.

-Brian
 
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filmmakerken

EOS R, EOS 10, FTb
CR Pro
Apr 12, 2020
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35
Virginia
www.cinefoundry.com
The C70 & speed booster are obviously aimed at shooters with existing Canon EF glass rather than those of us wanting to go all RF glass. The EF 24-105mm f/4L IS II USM is the same price (on B&H) as the RF 24-105mm f/4L IS USM but the "native" RF lens will have a crop factor. While I'm excited about the C70 there is still the issue that the Super 35 sensor negates some of the value of RF lenses. I own the RF 28-70mm f/2L, a much nicer lens than the three EF lenses compatible with the speed booster, but it becomes something along the lines of a 48-120mm with the Super 35 sensor.

I suspect Canon will eventually release this camera body with the R5's 8K full frame sensor, but not until they have more RF mount cinema lenses.
 
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I'm sure this will be a good product by Canon.

But at this price the C200 seems more attractive, mainly for the ultra chunky RAW codec.
Not sure who the C70 is for. At $5500 it's clearly not for the average V-Logger or amateur.
Those RF lenses can be expensive and the C70 seems designed to take the most advantage of them.

As of this moment it's exactly the same price as the C200, which also has the huge advantage
of being able to use tons of EF lenses natively.
 
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