40.0 m
Hyperfocal distance
20.0 m
Sharp from (focused at hyperfocal)
61 mm f/3.1
Full-frame equivalent
39°
Diagonal angle of view
Depth of field by subject distance#
40 mm at f/2 on APS-C (23.5×15.6 mm), circle of confusion 20 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) | 29.8 cm | 30.2 cm | 0.4 cm | 50% / 50% | 13.09% |
| 50.0 cm (1.64 ft) | 49.4 cm | 50.6 cm | 1.2 cm | 49% / 51% | 7.40% |
| 75.0 cm (2.46 ft) | 73.7 cm | 76.4 cm | 2.7 cm | 49% / 51% | 4.79% |
| 1.00 m (3.28 ft) | 97.7 cm | 1.02 m | 4.8 cm | 49% / 51% | 3.55% |
| 1.50 m (4.92 ft) | 1.45 m | 1.56 m | 11.0 cm | 48% / 52% | 2.33% |
| 2.00 m (6.56 ft) | 1.91 m | 2.10 m | 19.6 cm | 48% / 52% | 1.74% |
| 3.00 m (9.84 ft) | 2.79 m | 3.24 m | 44.6 cm | 46% / 54% | 1.15% |
| 4.00 m (13.1 ft) | 3.64 m | 4.44 m | 80.0 cm | 45% / 55% | 0.86% |
| 5.00 m (16.4 ft) | 4.45 m | 5.71 m | 1.26 m | 44% / 56% | 0.69% |
| 7.00 m (23.0 ft) | 5.96 m | 8.47 m | 2.51 m | 41% / 59% | 0.49% |
| 10.0 m (32.8 ft) | 8.01 m | 13.3 m | 5.31 m | 38% / 62% | 0.34% |
| 15.0 m (49.2 ft) | 10.9 m | 24.0 m | 13.0 m | 31% / 69% | 0.23% |
| 20.0 m (65.6 ft) | 13.3 m | 39.9 m | 26.6 m | 25% / 75% | 0.17% |
| 30.0 m (98.4 ft) | 17.2 m | 120 m | 102 m | 13% / 87% | 0.11% |
| 50.0 m (164 ft) | 22.2 m | ∞ | ∞ | — | 0.07% |
| 100 m (328 ft) | 28.6 m | ∞ | ∞ | — | 0.03% |
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#
Same lens settings on other formats#
When to use it#
At f/2, a 40 mm lens on APS-C is a natural choice for environmental portraits, street and low light. Focused at 3 m you get 44.6 cm of sharp zone; for maximum front-to-back sharpness focus at 40.0 m and everything from 20.0 m to infinity will be acceptably sharp.
See also the f/2 aperture guide.
Frequently asked questions#
What is the depth of field of a 40mm lens at f/2?
On APS-C, focused at 3 m, it is 44.6 cm; at 1 m it is 4.8 cm.
What is the hyperfocal distance for 40mm f/2?
40.0 m (131 ft) on APS-C. Everything from 20.0 m to infinity is acceptably sharp.
Last updated October 03, 2026 · How we calculate · Sources