Best telephoto lens for the canon eos r?

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From Canon EOS R: Canon EOS R: A mirrorless camera by Canon with a 30.3-megapixel full frame sensor, announced in 2018. Canon's first full-frame mirrorless body, now a common used buy. Specs - Maker: Canon - Mount: Canon RF - Sensor: Full frame, 36 x 24mm, crop factor 1.0 - Resolution: 30.3 megapixels - Stabilisation: none in the body; use stabilised lenses for slow shutter speeds - Announced: 2018 - Type: mirrorless camera Focal lengths on it ...

From Canon EOS 5DS R: Canon EOS 5DS R: A DSLR by Canon with a 50.6-megapixel full frame sensor, announced in 2015. The 5DS with its anti-aliasing effect cancelled, for slightly more detail.

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