Hey all. I'm new here. Let's say I have an old lens from a film camera; a 50mm. when I put it on my new camera, it works like a 75mm because of the 1.5 size difference of the sensor versus film. Ok. I get that. But what happens if I buy a modern "digital only" 50mm lens? Does it equate to 50mm? Is there anything printed on the lens to tell me if it will work as a 50mm or 75mm? Or do I just have to guess by knowing the age of the lens whether it was meant for full frame or apsc sensors?