Photography is not objective, but as a type of visual depiction and follows the rules of visual perception.

Many of these choices are hidden in optical, mechanical, chemical, and/or software design choices.

Tone and color choices in pictures

Consumer photographers do not normally make these choices. The choices were made by camera manufacturers, designed not just for accuracy, but to appeal to consumers’ aesthetic preferences.

• Tone choices in film

For much of the twentieth century, consumer photographers shot on film, and so the choices made by film and camera manufacturers played a large, hidden role in consumers’ pictures.

• For example, starting in the 1950s, Kodak calibrated their photochemical formulas and processes by photographing professional models, all of whom were White women, and then asking nonexpert viewers which photos they liked more.
• Based on these kinds of experiments, an early paper from Kodak concluded that “optimum reproduction of skin color is not ‘exact’ reproduction” (MacAdam, 1951). Viewers generally preferred images that made skin look pinker than in real life, and so this is what Kodak film did for a long time (Peter Hertzmann, 2022, as described to me by Peter Hertzmann, from his recollections from working at Kodak in the 1970s).
• Kodak film worked poorly for darker skin tones; only in the 1970s did Kodak begin to include darker skin tones in their calibration processes (Roth, 2009).

• Exposure choices in smartphone:
  • HDR: high-dynamic range light measurements
  • Night-time scenes

• Visual adaptation to darkness is simulated by bright highlights and dark shadows (chiaroscuro) or a blue-green tint (the Purkinje effect).
• Nowadays, smartphones automatically apply these techniques for low-light photos.
• The algorithm adds contrast and bluish tints to parts of an image.

Perspective choices in pictures

• linear vs. non-linear perspectives
  • linear perspective leads to problems, e.g. marginal distortion
• from linear to non-linear

  As computational perspective methods mature and become available on smartphones, we may no longer think of linear perspective as the default mode for photography.

Perception of pictures

Perception of photography should not be treated as equivalent to real-world vision.
Compelling evidenc
e shows that psychophysical and neurological responses differ for photos of objects versus for real objects (Pepperell, 2015; Snow & Culham, 2021).