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What it frames

The Canon EOS R8 Mark II with the Canon RF 7-14mm f/2.8-3.5L Fisheye STM, over an 8.5 m tree and a 1.75 m person, with hills behind. 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.

7mm on the Canon EOS R8 Mark II frames 103 m × 68.6 m at 20 m: like 7mm on full frame, 137° across.

24mm eq.50mm eq.135mm eq.7mm · like 7mm on full frame103 m × 68.6 m at 20 m
The subject is 20 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 20 m103 m × 68.6 m
  • Full-frame equivalent7mm
  • Angle of view137° × 119°, 144° diagonal
  • Depth of field at f/2.859 cm to infinity (to infinity)
  • Depth of field at f/821 cm to infinity (to infinity)
  • Hyperfocal at f/2.861 cm
  • Hyperfocal at f/822 cm
  • Circle of confusion0.029 mm
f/2.859 cm to infinity (everything to infinity)f/821 cm to infinity (everything to infinity)camerasubject, 20 m40 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.