19.1 m
Hyperfocal distance
9.54 m
Sharp from (focused at hyperfocal)
40 mm f/2.8
Full-frame equivalent
57°
Diagonal angle of view
Depth of field by subject distance#
40 mm at f/2.8 on full frame (36×24 mm), circle of confusion 30 µm. “Background blur” is the size of an out-of-focus light at infinity as a percentage of frame width.
| Focus distance | Near limit | Far limit | Total DoF | Front / behind | Background blur |
|---|---|---|---|---|---|
| 30.0 cm (0.98 ft) | 29.6 cm | 30.4 cm | 0.8 cm | 49% / 51% | 6.11% |
| 50.0 cm (1.64 ft) | 48.8 cm | 51.2 cm | 2.4 cm | 49% / 51% | 3.45% |
| 75.0 cm (2.46 ft) | 72.3 cm | 77.9 cm | 5.6 cm | 48% / 52% | 2.24% |
| 1.00 m (3.28 ft) | 95.2 cm | 1.05 m | 10.1 cm | 47% / 53% | 1.65% |
| 1.50 m (4.92 ft) | 1.39 m | 1.62 m | 23.1 cm | 46% / 54% | 1.09% |
| 2.00 m (6.56 ft) | 1.81 m | 2.23 m | 41.6 cm | 45% / 55% | 0.81% |
| 3.00 m (9.84 ft) | 2.60 m | 3.55 m | 95.5 cm | 42% / 58% | 0.54% |
| 4.00 m (13.1 ft) | 3.31 m | 5.05 m | 1.74 m | 40% / 60% | 0.40% |
| 5.00 m (16.4 ft) | 3.97 m | 6.76 m | 2.79 m | 37% / 63% | 0.32% |
| 7.00 m (23.0 ft) | 5.13 m | 11.0 m | 5.90 m | 32% / 68% | 0.23% |
| 10.0 m (32.8 ft) | 6.57 m | 21.0 m | 14.4 m | 24% / 76% | 0.16% |
| 15.0 m (49.2 ft) | 8.40 m | 69.9 m | 61.5 m | 11% / 89% | 0.11% |
| 20.0 m (65.6 ft) | 9.77 m | ∞ | ∞ | — | 0.08% |
| 30.0 m (98.4 ft) | 11.7 m | ∞ | ∞ | — | 0.05% |
| 50.0 m (164 ft) | 13.8 m | ∞ | ∞ | — | 0.03% |
| 100 m (328 ft) | 16.0 m | ∞ | ∞ | — | 0.02% |
Try other settings#
Near limit—
Far limit—
Depth of field—
Hyperfocal distance—
In front / behind—
40 mm at other apertures (subject at 3 m)#
Other focal lengths at f/2.8#
Same lens settings on other formats#
When to use it#
At f/2.8, a 40 mm lens on full frame is a natural choice for environmental portraits, street and low light. Focused at 3 m you get 95.5 cm of sharp zone; for maximum front-to-back sharpness focus at 19.1 m and everything from 9.54 m to infinity will be acceptably sharp.
See also the f/2.8 aperture guide.
Frequently asked questions#
What is the depth of field of a 40mm lens at f/2.8?
On full frame, focused at 3 m, it is 95.5 cm; at 1 m it is 10.1 cm.
What is the hyperfocal distance for 40mm f/2.8?
19.1 m (62.6 ft) on full frame. Everything from 9.54 m to infinity is acceptably sharp.
Last updated October 03, 2026 · How we calculate · Sources