EOS R, EF-S Lens Compatibility

[Pixschack]

Apparently with the adapter, EF-S lenses can be used on the new EOS R.  Will the EF-S 10-22mm ( for example) then be a true 10-22mm full frame lens on the EOS R?

[John_B · Accepted solution]

Hello Pixchack! 

Welcome to the Canon Forums and thanks for your inquiry!
The EOS R system is designed for full, uninhibited compatibility with all existing EF, EF-S, TS-E and MP-E lenses through the use of mount adapters. In addition, through the use of the optional Drop-In Filter Mount Adapter or Control Ring Mount Adapter these lenses, in fact, gain functionality.

 When attaching an EF-S lens via any of Canon’s new R-series mount adapters, the new EOS R automatically switches to APS-C crop mode.

[John_B · Accepted solution]

Hello Pixchack! 

Welcome to the Canon Forums and thanks for your inquiry!
The EOS R system is designed for full, uninhibited compatibility with all existing EF, EF-S, TS-E and MP-E lenses through the use of mount adapters. In addition, through the use of the optional Drop-In Filter Mount Adapter or Control Ring Mount Adapter these lenses, in fact, gain functionality.

 When attaching an EF-S lens via any of Canon’s new R-series mount adapters, the new EOS R automatically switches to APS-C crop mode.

[Pixschack]

Much appreciated.

[kvbarkley]

To technically answer your point, yes the 10-22 will be a 10-22 on the R. A mm is mm is mm. However, it is optimised for APS-C*, so I guess the R limits you.

*Infact, the image circle might only cover the area of the APS-C sensor.

[MikeSowsun · Accepted solution]

The EOS R is a 30 megapixel  (6720 x 4480) Full Frame camera.  If you use an adapter to mount an APS-C crop lens like the EF-S 10-22, the camera will automatically turn into a 11.6 megapixel (4176x2784) crop camera. 

It will not give you a Full Frame 10-22mm field of view. It will look like a 16-35mm FF equivalent. ( just like a crop camera will)

[kamilkp]

The automatic crop only happens when you put on one of Canon's crop lens i.e. an EF-S lens. But if you put on a third party crop-senor lens like a Tokina 11-20mm f/2.8 you are not forced into crop mode. From 16mm the lens covers the entire image circle so you can shoot full-resolution images with it and also high framerate videos. Check out my review of that combo here:

(Link removed as per forum guidlelines) 

[RobertTheFat]

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@kamilkp wrote:

The automatic crop only happens when you put on one of Canon's crop lens i.e. an EF-S lens. But if you put on a third party crop-senor lens like a Tokina 11-20mm f/2.8 you are not forced into crop mode. From 16mm the lens covers the entire image circle so you can shoot full-resolution images with it and also high framerate videos. Check out my review of that combo here:

(Link removed as per forum guidlelines) 

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I can think of circumstances where that behavior (trading resolution for coverage) might be advantageous. Is there a way to tell the R (using any of its adapters) to treat an EF-S lens that way?

[kamilkp]

I don’t think so. The Tokina lens is technically an EF lens. It has an EF mount and would fit even on a full frame DLSR like a 5D or 1D-X