Please can you help me Brian, I’m confused by the idea that smaller DSLR sensor sizes give a lens greater reach, when using the same lens as a full-frame camera?
Malcolm Meddings, Isle of Man
BRIAN SAYS… APS-C sized sensors are 22.4mm x 15mm, and this means that lenses will have a smaller angle of view than when fitted to a camera with a full-frame sensor 36mm x 24mm. The problem is that angle-of-view is expressed in degrees and not that easy to remember. Switching from full-frame to crop sensors, you can express the change in angle of view as a change in focal length, a 1.6x multiplier for ease of understanding, in this case. This gives rise to the notion that a crop sensor camera has greater reach with the same lens as a full-frame camera.