Editing Hyperfocal distance (section)

{{Short description|Distance beyond which all objects can be brought into an acceptable focus}}
[[File:Minox LX hyperfocal.JPG|thumb|Minox LX camera with hyperfocal red dot]]
[[File:Nikon 28mm lens at hyperfocus.jpg|right|thumb|[[Nikon]] 28mm {{f/|2.8}} lens with markings for the depth of field. The lens is set at the hyperfocal distance for {{f/|22}}. The orange mark corresponding to {{f/|22}} is at the infinity mark ({{math|∞}}). Focus is acceptable from under {{val|0.7|u=m}} to infinity.]]
[[File:Minolta 100-300 at hyperfocal distance.jpg|right|thumb|[[Minolta]] 100–300 mm zoom lens. The depth of field, and thus hyperfocal distance, changes with the focal length as well as the f-stop. This lens is set to the hyperfocal distance for {{f/|32}} at a focal length of {{val|100|u=mm}}.]]

In [[optics]] and [[photography]], '''hyperfocal distance''' is a distance from a lens beyond which all objects can be brought into an "acceptable" [[focus (optics)|focus]]. As the hyperfocal distance is the focus distance giving the maximum [[depth of field]], it is the most desirable distance to set the focus of a [[fixed focus lens|fixed-focus camera]].<ref name="Kingslake1951">{{cite book|title=Lenses in Photography: The Practical Guide to Optics for Photographers|last=Kingslake|first=Rudolf|publisher=Garden City Press|year=1951|location=Garden City, NY}}</ref> The hyperfocal distance is entirely dependent upon what level of sharpness is considered to be acceptable.

The hyperfocal distance has a property called "consecutive depths of field", where a lens focused at an object whose distance from the lens is at the hyperfocal distance {{mvar|H}} will hold a depth of field from {{math|''H''/2}} to infinity, if the lens is focused to {{math|''H''/2}}, the depth of field will be from {{math|''H''/3}} to {{mvar|H}}; if the lens is then focused to {{math|''H''/3}}, the depth of field will be from {{math|''H''/4}} to {{math|''H''/2}}, etc.

[[Thomas Sutton (photographer)|Thomas Sutton]] and George Dawson first wrote about hyperfocal distance (or "focal range") in 1867.<ref name=":0">{{cite book |first1=Thomas |last1=Sutton |first2=George |last2=Dawson |title=A Dictionary of Photography |url=https://archive.org/details/dictionaryofphot00sutt |location=London |publisher=Sampson Low, Son & Marston |year=1867 }}</ref> Louis Derr in 1906 may have been the first to derive a formula for hyperfocal distance. [[Rudolf Kingslake]] wrote in 1951 about the two methods of measuring hyperfocal distance.

Some cameras have their hyperfocal distance marked on the focus dial. For example, on the [[Minox]] LX focusing dial there is a red dot between {{val|2|u=m}} and infinity; when the lens is set at the red dot, that is, focused at the hyperfocal distance, the depth of field stretches from {{val|2|u=m}} to infinity.  Some lenses have markings indicating the hyperfocal range for specific [[f-stop]]s, also called a ''depth-of-field scale''.<ref>{{Cite book |last=Minolta |url=http://archive.org/details/md_zoom_images |title=Minolta MD Zoom Lenses owner's manual |year=1985 |pages=9}}</ref>