What does it mean to say that the ideal pinhole camera has an "infinite depth of field"?

According to Wikipedia, depth of field is "the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image". Given this definition, I'm inferring that infinite depth of field just means that the pinhole camera has sufficient focus to resolve all objects, regardless of their distances; is this correct?

I would appreciate it if people would please clarify this.

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    \$\begingroup\$ The word "ideal" is doing a lot of heavy lifting in that first sentence. Used in a scientific or technical context, it usually means "just consider the basic fundamental principles and ignore all the inconvenient complications that occur in reality." \$\endgroup\$ Feb 7, 2020 at 12:33
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    \$\begingroup\$ "In theory, the is no difference between theory and practice. In practice, there is." - Yogi Berra \$\endgroup\$ Feb 7, 2020 at 13:15

1 Answer 1


Yes, that means that everything is in focus (which implies that the sensor doesn't even need to be a plane).

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    \$\begingroup\$ Unfortunately, diffraction increases as the pinhole size decreases. So, although pinhole cameras have large depth of fields, they aren't sharp. (xenoid - I am sure that you realize this, but others may not) \$\endgroup\$
    – Mattman944
    Feb 7, 2020 at 8:09
  • \$\begingroup\$ But at least they're equally not-sharp over the entire (infinite) range, right? Objects don't become less sharp when they move away from or toward the camera. \$\endgroup\$ Feb 7, 2020 at 14:31
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    \$\begingroup\$ @mattman944 The OP said "ideal" :) \$\endgroup\$
    – xenoid
    Feb 7, 2020 at 15:56

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