Zoom or prime lenses

​Prime lenses may not be universally better than zooms, but they generally have important advantages in terms of aperture, sharpness, and contrast. With these lenses, the connection between focal length and composition is also more obvious, which makes it easier to understand composition issues.

A normal lens has a focal length equal to the diagonal of the imaging format. For 135-film (24×36 mm) this means about 43 mm, for 110-film (13×17 mm) about 20 mm, and for 120-film (60×60 mm) about 80 mm. Lenses with these focal lengths are called 'normal' because when a picture taken with a normal lens is viewed, objects in the image appear normal, i.e. neither stretched nor compressed in depth.

A telephoto lens has a focal length greater than the normal. It can be a tool for bringing distant objects closer and isolating them from their surroundings. These lenses are often described as 'compressing' the pictures and making them appear flatter. However, this is just a matter of distance to the object. The compression effect is the same as when moving back while keeping framing constant.

A wide-angle lens has a focal length shorter than the normal, typically 28 mm or 35 mm. This gives a wider field of view and a larger depth of field, allowing the photographer to include more of the environment and creating a feeling of being inside the scene rather than observing it from a distance. Furthermore, the larger depth of field makes zone focusing easier, which is helpful for taking photos of moving objects as in street photography. However, it also creates compositional challenges, like having to manage busy backgrounds and to control geometric distortion.

The enclosed picture from Dragør harbour area in Denmark is taken with a CONTAX RTS and a Carl Zeiss Distagon T* 28 mm f2.8 lens, which is widely regarded as an excellent classic 28 mm wide-angle lens.