Focal length and angle of view

In short: Focal length (in millimetres) determines how much of the scene fits in the picture. Short focal lengths (wide angle) show a lot; long ones (telephoto) magnify distant subjects.

In more detail: On full frame about 50 mm counts as normal focal length because it roughly matches human vision.

In detail

• Wide angle (14–35 mm): Landscapes, architecture, interiors; distorts at the edges.
• Normal (35–70 mm): Reportage, everyday.
• Telephoto (85–200 mm and more): Portraits, sport, animals; compresses depth and gives background blur.
• Zoom and prime: Zooms are flexible; primes are often faster and sharper.
• Crop factor: With a smaller sensor the focal length appears longer (sensorgroesse-und-bildqualitaet).
• Perspective: It changes with position, not focal length; “zooming with your feet” can pay off.
• Smartphone: Several lenses with fixed focal lengths simulate zoom.