Depth of Field (DOF) and Hyperfocal Distance
You may have wondered "How do pros make those wonderful landscapes where everything seems to be in focus?" Well, it is not merely by closing down the aperture of superb wide angle lenses. They maximize DOF (depth of field), the region of acceptable sharpness, by focusing at the hyperfocal distance. A simple function of lens focal length, aperture and the diameter of the Circle of Confusion.
The wider the angle of a lens, the shorter its focal length and deeper depth of field. So, as an example, an 18mm lens will have deeper (longer) depth of field than a 105mm. Also, the smaller the aperture you use the bigger the depth of field; i.e. in any given focal length lens, one gets more depth of field with it at f/16 than at f/4, for example. You may want to check a most practical and well illustrated guide on the subject of DOF and aperture here.
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The Circle of Confusion (CoC) has nothing to do with other camera brand users. It is the largest on-film or on-sensor circle that you can see as a well defined point on an 8×10 print at arms length; that is, when viewed at from a "normal" viewing distance of 2 to 3 feet. Anything larger is seen as a small circle, not a point and is therefore perceived as out of focus. For 35mm film and FX format the diameter of such circle is 0.025mm. Often rounded to 0.03, the exact number used here is 0.02501. For the Nikon DX (APS-C) digital sensor format, the number used here is 0.0200.
The calculator in the next page allows for you to use any CoC of your choice, via a drop down menu.
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These two sample images were shot at f/16. The one on top was made focusing at infinity, the image below was produced with the lens focused at its Hyperfocal Distance. Take notice of the sharpness of the bush on the right hand side of the frame and the expanded DOF all the way to the horizon when using Hyperfocal Distance. |
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Please forgive me the decimal fractions in the table below for 35mm film and Nikon FX format. It is hard enough to approximately set any distance on a lens. As long as it is close, it will look good.
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To download a printable pdf file of Hyperfocal tables for 35mm Film or FX format from 17mm to 1000mm, click here
However, bear in mind the formulas were derived for the ultimate theoretical simple lens, not the sophisticated zoom and telephoto lenses we now use. Nevertheless, the Hyperfocal Distances calculated from the formulas are pretty accurate for wide angle lenses.
For typical wide angle lenses on a DX format Nikon or Fujifilm Digital SLR, you may download a table here for your bag.
For other focal lengths or apertures, both DX digital and FX film, you may use the H & DOF calculator
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