Aperture curve

Aperture curves are curves drawn on zoom lenses that show the dependence of the depth of field on the focal length for various f-stops . They are used to determine the focus area and the hyperfocal distance . The curves are plotted on the surface of the lens in a two-dimensional diagram of focal length and object distance . Two curves are drawn for each f-number shown , one for the near point and one for the far point . In most cases, aperture curves are only drawn for a few selected f-numbers, the assignment of the curves to the f-numbers is usually done by color coding. ${\displaystyle f}$ ${\displaystyle g}$ ${\displaystyle k}$ ${\displaystyle d_{n}}$ ${\displaystyle d_{f}}$

example

Aperture curves on manual zoom lenses. (left: 28-80 mm, right: 80-200 mm)

Zoom lens 28-80mm: (left in the picture)
Set distance: 1.2 m	F-number	Focal length
		28 mm	35 mm	50 mm	70 mm
Focus range (in m)	22nd	0.6 - ∞	0.7-3.4	0.9 - 1.7	1 - 1.4
	8th	0.9 - 1.9	1 - 1.6	1 - 1.4	1.1-1.3
hyperfocal distance (in m)	22nd	1.2	1.8	3.7	7.3
	8th	3.3	5.1	10.5	20.5

Zoom lens 80-200mm: (on the right in the picture)
Set distance: 10 m	F-number	Focal length
		80 mm	100 mm	135 mm	150 mm	200 mm
Focus range (in m)	22nd	4.9 - ∞	6-30.5	7.3-15.8	7.7-14.2	8.6 - 12
	16	5.7-39.1	6.8-19.1	7.9-13.5	8.3-12.7	9-11.3
	11	6.5-21.1	7.5-15.1	8.5-12.3	8.7-11.7	9.2-10.9
hyperfocal distance (in m)	22nd	9.5	14.8	27	33.3	59.1
	16	13.4	20.9	38.1	47	83.5
	11	18.9	29.6	53.8	66.4	118.1