Depth of field by subject distance#
105 mm at f/1.8 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 |
|---|---|---|---|---|---|
| 30.0 cm (0.98 ft) | 30.0 cm | 30.0 cm | 0.0 cm | 50% / 50% | 133.66% |
| 50.0 cm (1.64 ft) | 49.9 cm | 50.1 cm | 0.1 cm | 50% / 50% | 65.98% |
| 75.0 cm (2.46 ft) | 74.8 cm | 75.2 cm | 0.3 cm | 50% / 50% | 40.41% |
| 1.00 m (3.28 ft) | 99.7 cm | 1.00 m | 0.6 cm | 50% / 50% | 29.12% |
| 1.50 m (4.92 ft) | 1.49 m | 1.51 m | 1.4 cm | 50% / 50% | 18.68% |
| 2.00 m (6.56 ft) | 1.99 m | 2.01 m | 2.5 cm | 50% / 50% | 13.75% |
| 3.00 m (9.84 ft) | 2.97 m | 3.03 m | 5.7 cm | 50% / 50% | 9.00% |
| 4.00 m (13.1 ft) | 3.95 m | 4.05 m | 10.2 cm | 49% / 51% | 6.69% |
| 5.00 m (16.4 ft) | 4.92 m | 5.08 m | 16.0 cm | 49% / 51% | 5.32% |
| 7.00 m (23.0 ft) | 6.85 m | 7.16 m | 31.5 cm | 49% / 51% | 3.78% |
| 10.0 m (32.8 ft) | 9.69 m | 10.3 m | 64.7 cm | 48% / 52% | 2.63% |
| 15.0 m (49.2 ft) | 14.3 m | 15.8 m | 1.46 m | 48% / 52% | 1.75% |
| 20.0 m (65.6 ft) | 18.8 m | 21.4 m | 2.61 m | 47% / 53% | 1.31% |
| 30.0 m (98.4 ft) | 27.3 m | 33.2 m | 5.91 m | 45% / 55% | 0.87% |
| 50.0 m (164 ft) | 43.0 m | 59.7 m | 16.7 m | 42% / 58% | 0.52% |
| 100 m (328 ft) | 75.4 m | 148 m | 73.0 m | 34% / 66% | 0.26% |
Try other settings#
105 mm at other apertures (subject at 3 m)#
Other focal lengths at f/1.8#
Same lens settings on other formats#
When to use it#
At f/1.8, a 105 mm lens on APS-C is a natural choice for portraits and subject isolation. Focused at 3 m you get 5.7 cm of sharp zone; for maximum front-to-back sharpness focus at 306 m and everything from 153 m to infinity will be acceptably sharp.
See also the f/1.8 aperture guide.
Frequently asked questions#
What is the depth of field of a 105mm lens at f/1.8?
On APS-C, focused at 3 m, it is 5.7 cm; at 1 m it is 0.6 cm.
What is the hyperfocal distance for 105mm f/1.8?
306 m (1005 ft) on APS-C. Everything from 153 m to infinity is acceptably sharp.
Last updated October 03, 2026 · How we calculate · Sources