On photography forums I see a lot of confusion about what is meant by prime lenses, zoom lenses, and telephoto lenses in particular. A zoom lens is able to change its focal length, i.e. to zoom in and out. This does not necessarily mean that it is a telephoto lens. A prime lens has a […]Read more "Prime, zoom, telephoto or wide angle lens?"
Consumer photographic lenses are almost always sold by their focal length when used on a 35mm camera (or full-frame professional DSLR). It’s already confusing enough to work out what their effective focal length is when used on an APS-C sensor (most consumer DSLRs), but since I’ve been getting into medium-format photography it’s even more confusing […]Read more "Focal lengths on different formats"