Depth of field by subject distance#
300 mm at f/2.8 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) | 75.0 cm | 75.0 cm | 0.1 cm | 50% / 50% | 198.41% |
| 1.00 m (3.28 ft) | 99.9 cm | 1.00 m | 0.1 cm | 50% / 50% | 127.55% |
| 1.50 m (4.92 ft) | 1.50 m | 1.50 m | 0.3 cm | 50% / 50% | 74.40% |
| 2.00 m (6.56 ft) | 2.00 m | 2.00 m | 0.6 cm | 50% / 50% | 52.52% |
| 3.00 m (9.84 ft) | 2.99 m | 3.01 m | 1.5 cm | 50% / 50% | 33.07% |
| 4.00 m (13.1 ft) | 3.99 m | 4.01 m | 2.8 cm | 50% / 50% | 24.13% |
| 5.00 m (16.4 ft) | 4.98 m | 5.02 m | 4.4 cm | 50% / 50% | 19.00% |
| 7.00 m (23.0 ft) | 6.96 m | 7.04 m | 8.8 cm | 50% / 50% | 13.33% |
| 10.0 m (32.8 ft) | 9.91 m | 10.1 m | 18.1 cm | 50% / 50% | 9.20% |
| 15.0 m (49.2 ft) | 14.8 m | 15.2 m | 41.2 cm | 49% / 51% | 6.07% |
| 20.0 m (65.6 ft) | 19.6 m | 20.4 m | 73.6 cm | 49% / 51% | 4.53% |
| 30.0 m (98.4 ft) | 29.2 m | 30.9 m | 1.66 m | 49% / 51% | 3.01% |
| 50.0 m (164 ft) | 47.8 m | 52.4 m | 4.65 m | 48% / 52% | 1.80% |
| 100 m (328 ft) | 91.5 m | 110 m | 18.8 m | 45% / 55% | 0.90% |
Try other settings#
300 mm at other apertures (subject at 3 m)#
Other focal lengths at f/2.8#
Same lens settings on other formats#
When to use it#
At f/2.8, a 300 mm lens on full frame is a natural choice for portraits and subject isolation. Focused at 3 m you get 1.5 cm of sharp zone; for maximum front-to-back sharpness focus at 1.1 km and everything from 536 m to infinity will be acceptably sharp.
See also the f/2.8 aperture guide.
Frequently asked questions#
What is the depth of field of a 300mm lens at f/2.8?
On full frame, focused at 3 m, it is 1.5 cm; at 1 m it is 0.1 cm.
What is the hyperfocal distance for 300mm f/2.8?
1.1 km (3516 ft) on full frame. Everything from 536 m to infinity is acceptably sharp.
Last updated October 03, 2026 · How we calculate · Sources