Depth of Field

This document I'm pretty much going to take standard information on because I agree with it. This document does not include movements available in large format cameras. So to Start, the dictionary definition of depth of Field is: the distance between the nearest and furthest objects in focus. There is parts to calculating the depth of field and each part having it's own formula and set of rules the parts are Hyperfocal Distance, Near Distance , and Far distance.

Hyperfocal Distance:

The distance in front of a lens that is focused at infinity beyond which all objects are well defined and clear formula is: H = (F² / Fs*c) + F H = Hyperfocal Distance F = Focal length: the mm of the lens (such as I have a portrait lens of 80mm) Fs = F/Stop. The lens f/stop C = Circle of confusion (aka circle of least confusion) for film format. (For now I'm just going to chart out a few calculation values because this a whole subject in-itself, and will write a different document for that)

Format	CoC
35mm	0.029
6x4.5	0.047
4x5	0.11

Near Distance:

The Distance in front of the focused distance of the lens which all object are well defined and clear. formula is:

N = ( S * (H - F) ) / ( H + S - ( 2 * F ) ) N = Near distance

S = Focused distance (in mm) H = Hyperfocal distance F = Focal length

Far Distance:

The Distance behind of the focased distatnce of the lens which all object are well defined and clear.

formula is, however is the answer is less than 0 Far Distance is infinity.

Fr = ( S * (H - F) ) / ( H - S )

Fr = Far distance

S = Focused distance (in mm) H = Hyperfocal distanceExample: 35mm camera, lens is 55m, F/stop 11, focus distance is 3048mm (10 feet)

	mm	Feet
Hyperfocal	9286.004	30.46589
Near Distance	2301.709	7.551539
Far Distatnce	4510.433	14.79807