667 m
Hyperfocal distance
334 m
Sharp from (focused at hyperfocal)
400 mm f/8.0
Full-frame equivalent
6°
Diagonal angle of view
Depth of field by subject distance#
400 mm at f/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 |
|---|---|---|---|---|---|
| 1.00 m (3.28 ft) | 99.9 cm | 1.00 m | 0.2 cm | 50% / 50% | 92.59% |
| 1.50 m (4.92 ft) | 1.50 m | 1.50 m | 0.5 cm | 50% / 50% | 50.51% |
| 2.00 m (6.56 ft) | 2.00 m | 2.00 m | 1.0 cm | 50% / 50% | 34.72% |
| 3.00 m (9.84 ft) | 2.99 m | 3.01 m | 2.3 cm | 50% / 50% | 21.37% |
| 4.00 m (13.1 ft) | 3.98 m | 4.02 m | 4.3 cm | 50% / 50% | 15.43% |
| 5.00 m (16.4 ft) | 4.97 m | 5.03 m | 6.9 cm | 50% / 50% | 12.08% |
| 7.00 m (23.0 ft) | 6.93 m | 7.07 m | 13.9 cm | 50% / 50% | 8.42% |
| 10.0 m (32.8 ft) | 9.86 m | 10.1 m | 28.8 cm | 49% / 51% | 5.79% |
| 15.0 m (49.2 ft) | 14.7 m | 15.3 m | 65.7 cm | 49% / 51% | 3.81% |
| 20.0 m (65.6 ft) | 19.4 m | 20.6 m | 1.18 m | 49% / 51% | 2.83% |
| 30.0 m (98.4 ft) | 28.7 m | 31.4 m | 2.67 m | 48% / 52% | 1.88% |
| 50.0 m (164 ft) | 46.5 m | 54.0 m | 7.48 m | 46% / 54% | 1.12% |
| 100 m (328 ft) | 87.0 m | 118 m | 30.6 m | 43% / 57% | 0.56% |
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 full frame is a natural choice for landscapes and architecture where front-to-back sharpness matters. Focused at 3 m you get 2.3 cm of sharp zone; for maximum front-to-back sharpness focus at 667 m and everything from 334 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 full frame, focused at 3 m, it is 2.3 cm; at 1 m it is 0.2 cm.
What is the hyperfocal distance for 400mm f/8?
667 m (2189 ft) on full frame. Everything from 334 m to infinity is acceptably sharp.
Last updated October 03, 2026 · How we calculate · Sources