>>3092010Yes and no.
Putting a full frame lens on a crop body does not increase the focal length. A 50mm on a crop is still a 50mm. What happens is, the crop camera sensor is too small to catch the image circle cast by the ff lens. This means part of image you would get on a FF senor is cut off. This 'cropped image' is the same as if you had taken the image on a ff sensor and cropped the ends.
The effectice fov changes due to this. Which is what people mean when they say a 50mm is 75mm equivalent on a crop body. They are saying the field of view is the same as if you had used a 75mm lens on a full frame body.