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 Today's cameras contain powerful microprocessors and sophisticated autofocus schemes.
They know what aperture is set and measure distance accurately every time you trip the shutter. Given that, messing around
with hyperfocal distance tables should be something we can forget about. Sadly, many of today's most sophisticated cameras, including Canon's EOS 1Ds Mark II and 1D Mark II, have no automatic
depth of field function. Further, even though these cameras "know" the exact distance to the subject, they have no way to communicate it to the user. On top of all this, today's high quality zoom lenses have no depth of field
markings, and their distance scales are so sparsely marked that it is difficult to determine the focus distance manually. Stopping the lens down and guessing whether close objects are adequately sharp in the darkened viewfinder is just ridiculous, but
that is often what must be done. When
there is adequate
time, I often use hyperfocal distance tables to set the focus point, or at least to roughly verify the guess made by peering into the stopped down and darkened viewfinder. These tables are simply
special depth of field tables. The hyperfocal distance is the distance at which you must focus your lens, at a given aperture, to get the maximum depth of field, while maintaining a point at
infinity in sharp focus. For landscape photographers, setting the correct hyperfocal distance is often very important.
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There are hyperfocal distance tables below for cameras with 1.6x and 1.3x magnification factors, as well as for full frame 35mm cameras. The same tables are available for download
in Microsoft Excel format. It is reasonable to use the 1.6x table for cameras with a 1.5x magnification factor,
though these cameras will produce slightly more depth of field than indicated by the table. These tables are most useful at wider than normal focal lengths, but the "full frame"
table goes all the way to 300 mm. If I get many requests to include longer focal lengths in the 1.3x and 1.6x tables, I may do so in the future.
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The "Focal Length" and "Aperture" columns in these tables should be obvious enough. The "Focus At" column gives the hyperfocal distance.
This is the distance at which you should focus your lens. Given the focal length, aperture, and focus settings, the "DOF From" column gives the minimum distance at, and beyond which, objects will appear sharp. You will note that there are entries for a few "odd" f-stops, like 6.3, 18, and 20. These are listed because the "focus at" distance for these f-numbers and focal
length combinations fall
close to one of the few marked distances on popular Canon lenses. In any case, the extra table entries hurt nothing.
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If you are familiar with depth of field calculations you already know that they depend on the size of the final print and associated diameter of something called the "circle of
confusion". You can read about all of the technicalities somewhere else. For now just be aware that all standard DOF / hyperfocal distance tables, like the ones below, are calculated based on 8x10 inch prints made from the given
sensor format. I often stop down one extra stop when possible to account for distance estimating errors and to add extra sharpness for larger print sizes. Having said that, please keep in
mind that using the smallest aperture on a
lens is a bad idea. At such small apertures diffraction will limit sharpness across the entire image. Note that larger
sensor sizes provide greater DOF at any given focal length / aperture / distance combination. This is because larger formats are enlarged less to produce prints of the same size. When
used for full frame sensors, the 1.3x table gives a "safety factor" of about 2/3 stop when compared to the full frame table. This means it can be used as a more conservative table for full frame
sensors if you wish.
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