2.0 km
Hyperfocal distance
1.0 km
Sharp from (focused at hyperfocal)
614 mm f/6.1
Full-frame equivalent
4°
Diagonal angle of view
Depth of field by subject distance#
400 mm at f/4 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) | 100.0 cm | 1.00 m | 0.1 cm | 50% / 50% | 283.69% |
| 1.50 m (4.92 ft) | 1.50 m | 1.50 m | 0.2 cm | 50% / 50% | 154.74% |
| 2.00 m (6.56 ft) | 2.00 m | 2.00 m | 0.3 cm | 50% / 50% | 106.38% |
| 3.00 m (9.84 ft) | 3.00 m | 3.00 m | 0.8 cm | 50% / 50% | 65.47% |
| 4.00 m (13.1 ft) | 3.99 m | 4.01 m | 1.4 cm | 50% / 50% | 47.28% |
| 5.00 m (16.4 ft) | 4.99 m | 5.01 m | 2.3 cm | 50% / 50% | 37.00% |
| 7.00 m (23.0 ft) | 6.98 m | 7.02 m | 4.6 cm | 50% / 50% | 25.79% |
| 10.0 m (32.8 ft) | 9.95 m | 10.0 m | 9.6 cm | 50% / 50% | 17.73% |
| 15.0 m (49.2 ft) | 14.9 m | 15.1 m | 21.9 cm | 50% / 50% | 11.66% |
| 20.0 m (65.6 ft) | 19.8 m | 20.2 m | 39.2 cm | 50% / 50% | 8.68% |
| 30.0 m (98.4 ft) | 29.6 m | 30.5 m | 88.8 cm | 49% / 51% | 5.75% |
| 50.0 m (164 ft) | 48.8 m | 51.3 m | 2.48 m | 49% / 51% | 3.43% |
| 100 m (328 ft) | 95.3 m | 105 m | 9.98 m | 48% / 52% | 1.71% |
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/4#
| Focal length | Subject at | Total DoF |
|---|---|---|
| 14 mm | 3.00 m | ∞ |
| 16 mm | 3.00 m | 42.9 m |
| 20 mm | 3.00 m | 5.55 m |
| 24 mm | 3.00 m | 2.99 m |
| 28 mm | 3.00 m | 2.00 m |
| 35 mm | 3.00 m | 1.21 m |
| 40 mm | 3.00 m | 90.8 cm |
| 50 mm | 3.00 m | 57.1 cm |
| 85 mm | 3.00 m | 19.4 cm |
| 105 mm | 3.00 m | 12.6 cm |
| 135 mm | 3.00 m | 7.5 cm |
| 200 mm | 10.0 m | 39.2 cm |
| 300 mm | 10.0 m | 17.2 cm |
| 400 mm | 10.0 m | 9.6 cm |
| 600 mm | 10.0 m | 4.2 cm |
Same lens settings on other formats#
When to use it#
At f/4, a 400 mm lens on APS-C is a natural choice for general photography. Focused at 3 m you get 0.8 cm of sharp zone; for maximum front-to-back sharpness focus at 2.0 km and everything from 1.0 km to infinity will be acceptably sharp.
See also the f/4 aperture guide.
Frequently asked questions#
What is the depth of field of a 400mm lens at f/4?
On APS-C, focused at 3 m, it is 0.8 cm; at 1 m it is 0.1 cm.
What is the hyperfocal distance for 400mm f/4?
2.0 km (6563 ft) on APS-C. Everything from 1.0 km to infinity is acceptably sharp.
Last updated October 03, 2026 · How we calculate · Sources