Hyperfocal Distance

Peter Putz
September 23, 2015

A web-based calculator for photographers

Photography and Hyperfocal Distance

In photography, the hyperfocal distance (HF) is the closest distance at which a lens can be focused while keeping objects at infinity acceptably sharp.

When the lens is focused at the HF, all objects at distances from half of the hyperfocal distance out to infinity will be acceptably sharp. This distance is called depth of field (DoF).

Challenge for a Photographer

The HF is dependent on camera, lens and exposure parameters. This is hard to calculate on the fly.

\[ HF = \frac{f^2}{ac / CF} + f \]

where

\[ \begin{aligned} HF & : \text{hyperfocal distance in mm} \\ f & : \text{focus length of lens in mm} \\ a & : \text{aperture in f-stops} \\ c & : \text{circle of confusion in mm} \\ CF & : \text{crop factor for film or image sensor size} \end{aligned} \]

Implementation in R

hyperfocDist <- function(f, a, cf) {
  HF <- round(
    ((f^2/(a*0.03/cf) + f)/1000),
    2)}

hf <- hyperfocDist(35, 4, 1.5)

print(hf)

[1] 15.35

Screenshot Shiny App

Source code on github