The equivalent focus length of full frame is about 75mm--Professional assistant for your Portrait photography.aps-c 50mm F1.2 adopts the optical structure of 7 elements in 5 groups. The minimum focusing distance is only 0.5m.How excellent F1.2 is: Light intake of F1.2 is 1.4 times F1.4 Light intake of F1.2 is 2.8 times F2 Light intake of F1.2 is 5.5 times F2.8 Light intake of F1.2 is 11.1 times F4The larger the aperture, the lower the sharpness. F1.2 is a good balance between the pursuit of a large aperture and image quality.Not only for portrait, but also for still object. Appropriat focal length with large aperture greatly expands the possibility of creation..