Like other lens makers, Nikon has its own technical jargon for the features and specifications of its lenses. The first bit of Nikon lens jargon is the name – Nikon brands its lenses ‘Nikkor’’ – though some reviewers and retailers us the name ‘Nikon’ instead, just to be clear about who makes them. Nikon camera […]
IF (Internal Focus)
Basic, older lenses are simply moved in and out to focus, but modern lenses have separate focus elements or focus groups inside them. The result is an internal focus (IF) system where the length of the lens (or its protrusion from the camera body) doesn't change when you focus.