1.0 km
Hyperfocal distance
500 m
Sharp from (focused at hyperfocal)
614 mm f/12.3
Full-frame equivalent
4°
Diagonal angle of view
Depth of field by subject distance#
400 mm at f/8 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 |
|---|---|---|---|---|---|
| 1.00 m (3.28 ft) | 99.9 cm | 1.00 m | 0.1 cm | 50% / 50% | 141.84% |
| 1.50 m (4.92 ft) | 1.50 m | 1.50 m | 0.3 cm | 50% / 50% | 77.37% |
| 2.00 m (6.56 ft) | 2.00 m | 2.00 m | 0.6 cm | 50% / 50% | 53.19% |
| 3.00 m (9.84 ft) | 2.99 m | 3.01 m | 1.6 cm | 50% / 50% | 32.73% |
| 4.00 m (13.1 ft) | 3.99 m | 4.01 m | 2.9 cm | 50% / 50% | 23.64% |
| 5.00 m (16.4 ft) | 4.98 m | 5.02 m | 4.6 cm | 50% / 50% | 18.50% |
| 7.00 m (23.0 ft) | 6.95 m | 7.05 m | 9.2 cm | 50% / 50% | 12.89% |
| 10.0 m (32.8 ft) | 9.90 m | 10.1 m | 19.2 cm | 50% / 50% | 8.87% |
| 15.0 m (49.2 ft) | 14.8 m | 15.2 m | 43.8 cm | 49% / 51% | 5.83% |
| 20.0 m (65.6 ft) | 19.6 m | 20.4 m | 78.4 cm | 49% / 51% | 4.34% |
| 30.0 m (98.4 ft) | 29.1 m | 30.9 m | 1.78 m | 49% / 51% | 2.88% |
| 50.0 m (164 ft) | 47.6 m | 52.6 m | 4.97 m | 48% / 52% | 1.72% |
| 100 m (328 ft) | 90.9 m | 111 m | 20.1 m | 45% / 55% | 0.85% |
Try other settings#
Near limit—
Far limit—
Depth of field—
Hyperfocal distance—
In front / behind—
400 mm at other apertures (subject at 3 m)#
Other focal lengths at f/8#
Same lens settings on other formats#
When to use it#
At f/8, a 400 mm lens on APS-C is a natural choice for landscapes and architecture where front-to-back sharpness matters. Focused at 3 m you get 1.6 cm of sharp zone; for maximum front-to-back sharpness focus at 1.0 km and everything from 500 m to infinity will be acceptably sharp.
See also the f/8 aperture guide.
Frequently asked questions#
What is the depth of field of a 400mm lens at f/8?
On APS-C, focused at 3 m, it is 1.6 cm; at 1 m it is 0.1 cm.
What is the hyperfocal distance for 400mm f/8?
1.0 km (3282 ft) on APS-C. Everything from 500 m to infinity is acceptably sharp.
Last updated October 03, 2026 · How we calculate · Sources