SHOOTING ON FILM NOTES – Ing. Jana Horáčková

APERTURE AND SHUTTER SPEED SETTINGS

When shooting from hand, as a general rule, the shutter speed should not exceed the focal length of the lens. For example, if you are shooting with a 200mm lens, your shutter speed should be 1/200 second or faster to get a sharp image.

The aperture number is the number you see on the camera or lens when adjusting the aperture size. Because f-stops are fractions, an aperture of f/2 is much larger than an aperture of f/16. Like the pupil in your eye, a large aperture lets in a lot of light. If your goal is to create an image with a shallow depth of field where the subject appears sharp while the foreground and background appear blurred, you should use very wide apertures such as f/1.8 or f/2.8 (for example, if you are using the lens 50mm f / 1.8 you should set the lens aperture to f / 1.8).

COLOR PERCEPTION AND TETRACHROMACY

VISION: Humans generally have 3 types of light-sensitive cells in their eye, (named cones) that are sensitive to color (this condition is called trichromacy) and one type of light-sensitive cells sensitive to the dimness of the scale gray (named rods). Such a person can recognize 10-25,000,000 colors (sources vary).

Some people may have a mutation and have 4 distinct cones in their eye instead of three (this condition is called tetrachromacy). Such a person is said to recognize up to 100,000,000 colors.

COMPARISON: HUMAN SIGHT 10-25,000,000 colors X DIGITAL PHOTO 16,777,216 colors X HUMAN SIGHT WITH TETRACHROMACY 100,000,000 colors

PHOTOGRAPHY: A common digital photo taken with a camera or mobile phone has: 16,777,216 colors (technical note: 8 bits per one channel x 3 RGB channels = 24bit).

Digitally, on some cameras, you can also take photos with a higher color sensitivity in the so-called RAW format, which distinguishes 68,719,476,736 colors (36bit) (12-16bit per channel x 3 channels RGB/36-48bit). RAW can be converted with a high number of colors into TIFF format, which can be opened by some programs, such as Adobe Photoshop. The disadvantages are that the RAW format itself can only be opened in a special editor, such files are very voluminous and if the system can process them correctly (graphics card, browser) most monitors cannot display them completely/properly, because they can only display 24bit (for example, EIZO brand monitors and i others can switch to more colors). Some graphics cards can switch to 10 bits per RGB channel. Even Photoshop can handle 10 bits and that corresponds to 1,070,000,000 colors.