How to know or calculate depth of field of a photo from EXIF tags?

Question

I want to know the depth of field of a photo, preferably in cm or m. I know that we can know the camera setting by reading the EXIF tags, but is there a tag directly telling us the depth of field? Or how can we calculate it from some EXIF tags? Examples would be appreciated. Thanks!

Answer 1

You can do this only if the exifs display the focus distance for the specific image. It is not frequent to have this information in the exifs. Hope this helps, JF

Answer 2

Calculating depth of field:

t = A * (S/1440) * (D - F) / F^2

The near focus distance = D/(1+t)

The far focus distance = D/(1-t)

And the full depth of field is the difference between these.

The variables are:

A = lens aperture (F Number)

S = camera sensor or film plane diagonal size in mm

D = focus distance in mm

F = lens focal length in mm

The sharpness of focus is subjective, and is adjusted by changing the constant in the calculation of the circle of confusion (CoC). This example uses CoC = S/1440, a commonly used value.