Portrait lens

Domestic portrait lens " Helios-40-2 " 1,5 / 85

Special portrait lenses feature a small number of lenses and air / glass borders. The first in the history of photography portraiture is considered to be the Petzval lens , created in 1840 for daguerreotype ^[4] . In the 1920s , portrait lenses designed by Nicola Persheid , manufactured by Emil Busch AG ^[5] , gained popularity. Triplet Cook and Zeiss Planar , created by Harold Taylor and Paul Rudolph at the end of the 19th century, played a large role in the development of lens construction. Petsval’s, Triplet and Planar lenses served as the basis for most modern portrait anastigmatics ^[6] . The latter include, for example, " Nikkor 85 / 1.4" and 85 / 1.8, "Canon EF 85 / 1.8 USM", "Minolta MAXXUM AF 85 / 1.4", the domestic series " Jupiter " and " Helios ” ^{[7] [8] [9] [3]} . Among the latest developments there are lenses (for example, “Canon EF 85 / 1,2L USM”) containing aspherical elements providing record values ​​of aperture ratio.

Another feature of portrait lenses is considered to be the preferred aperture device that provides a circular cross section of light beams. This allows you to get the highest quality picture due to the correct shape of a separate scattering circle ^[3] . Due to the design features, jumping apertures of modern SLR cameras are difficult to achieve with a circular opening, and in some cases, preference may be given to lenses with a classic aperture mechanism, generally accepted for rangefinder cameras . So, the Krasnogorsk Mechanical Plant resumed production of the classic Helios-40-2 lens with a bayonet mount of modern Nikon AI-S and Canon EF standards ^[10] . Thanks to the manual drive, the preset diaphragm consists of 10 blades, providing an almost round hole . Such retro-lenses, despite the shortcomings, are popular among amateur photographers, since modern autofocus optics with similar parameters are much more expensive ^[7] .

The focal lengths of portrait photo lenses designed for a small format frame usually lie in the range of 70-150 mm, depending on the preferred size of the plan. A focal length of 85 mm is considered classic, which is most suitable for a “waist-length” portrait, and exactly twice the size of the frame. Filming lenses designed for an “ academic ” frame or Super-35 format are most suitable for shooting close-ups of actors at the same focal lengths of 70-150. For amateur digital SLR cameras equipped with an APS-C matrix, a lens with a focal length of 50 or 58 mm, approximately equal to a doubled diagonal of ~ 27 mm ^{[* 1],} can be considered portrait. For medium-format cameras with a frame of 6 × 6 cm, lenses with a focal length of 150 mm to 200 mm are considered portrait.

Unlike other lenses, portrait lenses are less critical to optical perfection, allowing for residual aberration ^[11] . Deficiencies such as astigmatism , vignetting, and spherical aberration make it possible to highlight the face of the person being portrayed and hide skin defects ^[3] . Therefore, as a portrait, aplanates and even the simplest Monocle lens can be used ^{[12] [13]} . Some portrait lenses of the first half of the 20th century (for example, “Cooke Portrait”) provided for the ability to adjust the softness of the image by shifting individual lenses or an additional aperture (diffuser) inserted between the lenses ^[14] .

Another legend of portrait optics of those years - “Rodenstock Imagon” - provided for interchangeable diaphragm diffusers that were inserted into the frame depending on the required degree of blur. Around the main hole located in the center of the diaphragm, smaller additional holes were drilled, creating a characteristic optical pattern ^[15] . In the mid-1930s, Ernst Leitz also launched the Thambar 90mm f / 2.2 soft-focus portrait lens for Leica cameras. A transparent nozzle with a black circle with a diameter of 13 mm in the center was supplied. When a filter of this design is put on the lens, their central part, which gives the sharpest image, is “cut out” of light beams ^[16] .

Instead of adjusting the overall sharpness, modern manufacturers (for example, Nikon ) use the blur control technology for unfocused parts of the image, which has received the trade name "Defocus Image Control" ^[17] . This is achieved by changing the degree of spherical aberration with the help of a movable rear lens, moved by a separate ring of the frame with an additional scale, marked in aperture numbers ^[18] . Lenses of this design in the marking have additional letters “DC” and allow you to change the nature of the bokeh in front of the focus area, or behind it ^[19] . The Canon EF 135 / 2.8 Soft focus lens, declared by the manufacturer as a specialized portrait lens, has a similar design ^[20] .

Sony releases the Sony STF 135mm f / 2.8 T4.5 lens with the proprietary function for changing the softness of the picture “Smooth Trans Focus” ^[19] . Fuji also launches a lens with a "bokeh enhancing" apodization element, Fujinon 50 / 1.2.

In 2013, the Lomographic Society , using the Kickstarter voluntary donation service, raised $ 1.3 million for the release of the modern version of the New Petzval 2.2 / 85 lens for 35 mm cameras with Nikon and Canon EF mounts ^{[21] [22]} . The design was re-calculated by the Russian optician V. Bogdankov for digital cameras ^[23] . The production of lenses was established in 2014 at the Krasnogorsk Mechanical Plant, and at the moment they are sold at a price of $ 600 ^[24] . The lens is equipped with an insertable diaphragm, providing a perfectly round section of light beams.

Examples of inexpensive lenses that can be used with small format cameras as portrait ones:

• Canon EF 2.8 / 135; Canon EF 1.8 / 85;
• Nikkor 2.0 / 85; Nikkor 2.5 / 105;
• Sony 2/100;
• Sigma 1.4 / 85;
• Tamron 2.8 / 90;
• Helios-40-2 (1.5 / 85; lin / mm: 32 center, 16 edge; threaded connection M42 × 1 );
• Jupiter-9 2/85;
• Jupiter-11A (4/135; adapter);
• Jupiter-37A (3.5 / 135; adapter);

Professional portrait lenses on a small format frame:

• Carl Zeiss 1.4 / 85 Planar T *;
• Leica 2.0 / 90 APO SUMMICRON ( Leica M mount and Leica R mount );
• AF DC Nikkor 2.0 / 135; AF DC Nikkor 2.0 / 105; AF-S Nikkor 1.4 / 85 G;
• Canon EF 1.2 / 85L USM II;
• Sony Carl Zeiss 1.4 / 85 SAL T * ZA ( A mount );
• Sony STF 135mm f / 2.8 T4.5
• Sony Carl Zeiss Sonnar T ^* 135 / 1.8 ZA
• Samyang 1.4 / 85 IF - 2009;

Examples of lenses for medium format cameras :

• Carl Zeiss Jena Biometar (2.8 / 120 Bayonet B ),
• Carl Zeiss Jena Sonnar (2.8 / 180 Bayonet B ),
• Vega-28B (2.8 / 120; B-mount )
• Kaleinar-3 ( ARSAT MC ) (2.8 / 150 bayonet B or bayonet C ),

• Telephoto lens
• Close-up
• Portrait

• Andrey Akimov, Andrey Parshev. Management of understatement (rus.) // “Foto & video”: magazine. - 2008. - No. 5 . - S. 72-75 .

• B. Bakst. Genetics of absolute vision (Russian) // "Photocourier": journal. - 2006. - No. 7 (115) . - S. 16-24 .

• D.S. Volosov . § 4. Fast lenses // Photographic optics. - 2nd ed. - M .: "Art", 1978. - S. 310—329. - 543 p. - 10,000 copies.

• N. D. Panfilov, A. A. Fomin. Quick reference amateur photographer / N. N. Zherdetskaya. - M .: "Art", 1985. - S. 179-184. - 367 p. - 100,000 copies.

• V.V. Puskov. A brief photographic guide / I. Katsev. - M .: Goskinoizdat, 1952.- 423 p. - 50,000 copies.

• Vladimir Samarin. Portrait optics. Part I (Russian) // “Photo Shop”: magazine. - 2003. - No. 5 . - S. 38-40 . - ISSN 1029-609-3 .

• Fomin A.V. § 5. Photographic lenses // General course of photography / T. P. Buldakova. - 3rd. - M .: "Legprombytizdat", 1987. - S. 12-25. - 256 s. - 50,000 copies.

• Barbara Lowry. Cooke lenses from England (Russian) // Photocourier: magazine. - 2007. - No. 6 (126) . - S. 13-20 .

• The general theory of Rauschenbach's perspective through the eyes of a photographer (Russian) . "Phototour". Date of treatment November 16, 2015.