What it frames

The Fujifilm X100T with its built-in 23mm f/2 lens, over a 1.75 m person in a street, with a door, a parked car and buildings. Everything is drawn to scale: the solid frame is what the camera takes in, the dashed ones are 24, 50 and 135mm on full frame from the same spot. Its APS-C sensor (23.5 x 15.6 mm) has a crop factor of 1.5, so the dashed frames are marked with the focal length that gives the same view on it.

23mm on the Fujifilm X100T frames 5.11 m × 3.39 m at 5 m: like 34mm on full frame, 54° across.

24mm eq. (16mm)50mm eq. (33mm)135mm eq. (90mm)23mm · like 34mm on full frame5.11 m × 3.39 m at 5 m
The subject is 5 m away; things behind it are drawn smaller, as the camera sees them.
Inside the frame: the picture you would get.

The numbers

  • Frame at 5 m5.11 m × 3.39 m
  • Full-frame equivalent34mm
  • Angle of view54° × 37°, 63° diagonal
  • Depth of field at f/23.69 m to 7.74 m (4.04 m)
  • Depth of field at f/82.07 m to infinity (to infinity)
  • Hyperfocal at f/214.1 m
  • Hyperfocal at f/83.54 m
  • Circle of confusion0.019 mm
f/23.69 m to 7.74 m (4.04 m)f/82.07 m to infinity (everything to infinity)camerasubject, 5 m10 m
Depth of field: what is acceptably sharp, wide open and at f/8, focused on the subject.

How it is worked out

The frame at a distance is distance × sensor size ÷ focal length, across and up; the angle of view is 2 × atan(sensor size ÷ (2 × focal length)). Depth of field uses the thin-lens formulas: the hyperfocal distance H = f² ÷ (N × c) + f, the near limit s(H − f) ÷ (H + s − 2f) and the far limit s(H − f) ÷ (H − s), sharp to infinity from H on, with a circle of confusion c of the sensor diagonal ÷ 1500 and, on a zoom whose aperture changes, the maximum aperture taken linearly between its ends. These are for a rectilinear lens; a fisheye takes in more. Ask for this page with Accept: application/json for the numbers alone.