A while back Partner in Climb bought me a fancy adapter for mounting my full-size camera lenses on my Pentax Q. The 5.6x crop factor means that even my fisheye is a minimum of 56mm equivalent focal length, which makes using full-scale lenses for wide work basically impossible.
On the other side of the scale, my cheapo Tamron 70-300mm zoom becomes a whopping 390-1680mm zoom lens (as well as looking patently ridiculous attached to such a tiny camera). A few minutes ago I took it outside.
It’s not the sharpest, it’s not the most detailed, but hell to that – I can see craters on the moon! I have got to fetch my tripod from my parents house (and find a sharper long lens).