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14. Are there some simpler approximate formulas for depth of field?




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This article is from the Photographic Lenses FAQ, by David Jacobson with numerous contributions by others.

14. Are there some simpler approximate formulas for depth of field?

Yes. When the object distance is small with respect to the hyperfocal distance, the front and rear depth of field are almost equal and depend only on the magnification and effective f-stop and the following approximate formulas can be used.

frontdepth = reardepth = Ne*c/M^2
frontdepth = reardepth = So/hr

In non-macro situations Ne is the same as the marked f-number.

 

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previous page: 13. Where should I focus my lens so I will get everything from some close point to infinity in focus?
  
page up: Photographic Lenses FAQ
  
next page: 15. I have heard that one should use a long lens to get a shallow depth of field and a short lens to get a large depth of field. Is this true?