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To photograph outdoor night sports with an ISO 400–speed imaging medium, search Table 2 for "Night sports" (which has an EV of 9 for ISO 100), and add 2 to get EV 400 = 11. For lower ISO speed, decrease the exposure values (increase the exposures) by the number of exposure steps by which the speed is less than ISO 100.
Tri-X 400 is the more common of the two, available in 24- and 36-exposure rolls of 35 mm and rolls of 120 as well as 50 and 100 ft bulk rolls of 35 mm. Tri-X 320 is available in 4×5", 5×7", and 8×10" sheets. Tri-X 400 is usually rated at ISO 400 when processed in standard developers and remains among the fastest black and white films today.
Film speed is used in the exposure equations to find the appropriate exposure parameters. Four variables are available to the photographer to obtain the desired effect: lighting, film speed, f-number (aperture size), and shutter speed (exposure time). The equation may be expressed as ratios, or, by taking the logarithm (base 2) of both sides ...
DX CAS code positions; this film is rated at ISO 400/27°, has a 24-exposure length, and an exposure tolerance of ±1 stops. 1: Ground; 2–6: Film speed; 7: Ground; 8–10: Film length; 11–12: Exposure latitude; The outside of film cartridges are marked with a DX Camera Auto Sensing (CAS) code readable by many cameras.
On a sunny day with ISO 400 film / setting and aperture at f /16, set shutter speed to 1 / 400 or 1 / 500 . As with other light readings, shutter speed can be changed as long as the f-number is altered to compensate, e.g. 1 / 250 second at f /11 gives equivalent exposure to 1 / 125 second at f /16.
Exposure is a combination of the length of time and the illuminance at the photosensitive material. Exposure time is controlled in a camera by shutter speed, and the illuminance depends on the lens aperture and the scene luminance. Slower shutter speeds (exposing the medium for a longer period of time), greater lens apertures (admitting more ...
For example, an EV of 10 may be achieved with an aperture of f / 2.8 and a shutter speed of 1/125 s. The same exposure is achieved by doubling the aperture area to f / 2 and halving the exposure time to 1/250 s, or by halving the aperture area to f / 4 and doubling the exposure time to 1/60 s; in each case the response of the film is expected ...
The exposure range of a device is usually expressed in stops, which are equivalent to where c is the medium or device's contrast ratio. For example, average Digital Video (DV) has a contrast ratio of 45:1, so its exposure range is roughly 5.5 stops. [1] Film has an exposure range of approximately 14 stops. [2]