This vlog is about a Viltrox speed booster adapter that how it reduces the focal length by 0.71x and how it provides an extra f-stop with the full-frame lens on the Canon M50 mirrorless crop body. Also by mounting it, one can achieve functions of AF(autofocus) and adjustable aperture, etc. This Viltrox adapter can convert your EF lens like 24-105 F4L into F2.8L, similarly, you can use your other lenses like EF 50mm F1.8 lens as a 50mm F1.2 lens. If you cannot afford to buy canon expensive lenses like EF 27-70 2.8L or any last 50mm prime of the L series, then you should definitely try this adapter with less expensive canon full-frame lenses on the crop body. In this way, your lens will become faster and you can enjoy a more shallow depth of field in your photos.