Focusing at the hyperfocal distance (in feet in chart below) for these aperture and lens focal length
combinations will give you "adequate sharpness" from one half the hyperfocal distance to infinity
("adequate sharpness" is a somewhat subjective term).
Also, if the lens if focused at half the hyperfocal distance (H / 2), the depth of field (range of
"adequate sharpness") will extend from H / 3 to H.
| f 1.4 | f 2 | f 2.8 | f 4 | f 5.6 | f 8 | f 11 | f 16 | f 22 | f 32 | |
| 16mm | 20 | 14 | 10 | 7 | 5 | 3.5 | 2.6 | 1.8 | 1.3 | 0.9 |
| 24mm | 45 | 32 | 23 | 16 | 11 | 8 | 5.8 | 4.0 | 2.9 | 2.1 |
| 35mm | 96 | 67 | 48 | 34 | 24 | 17 | 12 | 8.5 | 6.2 | 4.3 |
| 50mm | 195 | 137 | 98 | 69 | 49 | 34 | 25 | 17 | 13 | 8.7 |
| 70mm | 383 | 268 | 192 | 134 | 96 | 67 | 49 | 34 | 25 | 17 |
| 85mm | 565 | 395 | 282 | 198 | 141 | 99 | 72 | 50 | 36 | 25 |
| 100mm | 781 | 547 | 391 | 274 | 196 | 137 | 100 | 69 | 50 | 35 |
| 135mm | 1424 | 997 | 712 | 499 | 356 | 250 | 182 | 125 | 91 | 63 |
| 200mm | 3125 | 2188 | 1563 | 1094 | 782 | 547 | 398 | 274 | 199 | 137 |
| 300mm | 7031 | 4922 | 3516 | 2462 | 1759 | 1231 | 896 | 616 | 448 | 309 |
http://www.outsight.com/hyperchart.php
The formula for hyperfocal distance is (f ^ 2 / Nc) + f
Where
f = the focal length of the lens (in mm).
N = the f-number (aperture) of the lens (2.8, 4, 5.6, etc)
c = the circle of confusion limit
(the value of c is 0.030 for a 35mm or digital "full frame" camera)
(c = 0.019 mm for a Canon crop digital camera)
(c = 0.020 mm for a Nikon crop digital camera)
(c = 0.015 mm for a Four-Thirds digital camera)
Note that the "+ f" on the end of equation is generally not significant (you'll get almost the same result without).
For any lens with given focal length, aperture (f-number), circle of confusion, AND focus distance, it is possible to calculate the near and far distances of "acceptable sharpness".
D-near = (s(H - f)) / (H + s - 2f)
D-far = (s(H - f)) / (H - s)
Where s = focus distance, H = hyperfocal distance (and other variables are as explained above)