Lenses are always identified by their focal length. It’s not just a physical measurement, it’s an indication of the type of lens it is, for example, a wideangle lens, standard lens, telephoto and so on. In other words, the focal length of the lens gives you an indication of its angle of view. Or at […]
Used to work out the effective focal length of lenses on cameras which don't have full frame sensors. You multiply the actual focal length by the crop factor to get the effective focal length. The crop factor of an APS-C camera is 1.5, so a 50mm lens has an effective focal length of 75mm.
In the days of film, it was well understood that the bigger the negative, the better the quality of the picture. The same is true with digital cameras, only here the ‘negative’ is the sensor. The larger the sensor size, the better (generally) the picture quality. Megapixels do confuse the issue somewhat because you can […]