Depth of field by subject distance#
300 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 |
|---|---|---|---|---|---|
| 75.0 cm (2.46 ft) | 74.9 cm | 75.1 cm | 0.2 cm | 50% / 50% | 69.44% |
| 1.00 m (3.28 ft) | 99.8 cm | 1.00 m | 0.4 cm | 50% / 50% | 44.64% |
| 1.50 m (4.92 ft) | 1.50 m | 1.50 m | 1.0 cm | 50% / 50% | 26.04% |
| 2.00 m (6.56 ft) | 1.99 m | 2.01 m | 1.8 cm | 50% / 50% | 18.38% |
| 3.00 m (9.84 ft) | 2.98 m | 3.02 m | 4.3 cm | 50% / 50% | 11.57% |
| 4.00 m (13.1 ft) | 3.96 m | 4.04 m | 7.9 cm | 50% / 50% | 8.45% |
| 5.00 m (16.4 ft) | 4.94 m | 5.06 m | 12.5 cm | 49% / 51% | 6.65% |
| 7.00 m (23.0 ft) | 6.88 m | 7.13 m | 25.0 cm | 49% / 51% | 4.66% |
| 10.0 m (32.8 ft) | 9.75 m | 10.3 m | 51.8 cm | 49% / 51% | 3.22% |
| 15.0 m (49.2 ft) | 14.4 m | 15.6 m | 1.18 m | 48% / 52% | 2.13% |
| 20.0 m (65.6 ft) | 19.0 m | 21.1 m | 2.11 m | 47% / 53% | 1.59% |
| 30.0 m (98.4 ft) | 27.8 m | 32.6 m | 4.78 m | 46% / 54% | 1.05% |
| 50.0 m (164 ft) | 44.1 m | 57.6 m | 13.5 m | 43% / 57% | 0.63% |
| 100 m (328 ft) | 79.0 m | 136 m | 57.2 m | 37% / 63% | 0.31% |
Try other settings#
300 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 300 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 4.3 cm of sharp zone; for maximum front-to-back sharpness focus at 375 m and everything from 188 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 300mm lens at f/8?
On full frame, focused at 3 m, it is 4.3 cm; at 1 m it is 0.4 cm.
What is the hyperfocal distance for 300mm f/8?
375 m (1231 ft) on full frame. Everything from 188 m to infinity is acceptably sharp.
Last updated October 03, 2026 · How we calculate · Sources