Best portrait lens for the leica sl2 s?

Here is what the site says about that.

From Leica SL2-S: Leica SL2-S: A mirrorless camera by Leica with a 24-megapixel full frame sensor, announced in 2020. The 24-megapixel SL2, better suited to low light and video. Specs - Maker: Leica - Mount: L-Mount - Sensor: Full frame, 36 x 24mm, crop factor 1.0 - Resolution: 24 megapixels - Stabilisation: in the body - Announced: 2020 - Type: mirrorless camera Focal lengths on it Full frame is the reference size: lenses frame as ...

From Leica SL2: Adapting lenses: Sigma's MC-21 adapts Canon EF lenses with autofocus.

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