What it frames
The Fujifilm X-T30 III with the Laowa 65mm f/2.8 2X Ultra Macro APO, over a 1.75 m person in front of a wall with a window. 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.
65mm on the Fujifilm X-T30 III frames 54 cm × 36 cm at 1.5 m: like 98mm on full frame, 20° across.
The numbers
- Frame at 1.5 m54 cm × 36 cm
- Full-frame equivalent98mm
- Angle of view20° × 14°, 24° diagonal
- Depth of field at f/2.81.47 m to 1.53 m (5.4 cm)
- Depth of field at f/81.43 m to 1.58 m (15 cm)
- Hyperfocal at f/2.880.3 m
- Hyperfocal at f/828.2 m
- Circle of confusion0.019 mm
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.