Search results
Results from the WOW.Com Content Network
Note that the times are approximate, and vary between different films and ASA numbers, but the table shows in general how the exposure time is adjusted. In photography , reciprocity is the inverse relationship between the intensity and duration of light that determines the reaction of light-sensitive material.
Photographic emulsion is a light-sensitive colloid used in film-based photography. Most commonly, in silver-gelatin photography , it consists of silver halide crystals dispersed in gelatin . The emulsion is usually coated onto a substrate of glass , films (of cellulose nitrate , cellulose acetate or polyester ), paper, or fabric.
It is common to express exposure increments in EV, as when adjusting exposure relative to what a light meter indicates (Ray 2000, 316). For example, an exposure compensation of +1 EV (or +1 step) means to increase exposure, by using either a longer exposure time or a smaller -number. The sense of exposure compensation is opposite that of the EV ...
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 ...
Structurally, collodion wet plates are held together with a specific emulsion type, made using a silver halide mixture in gelatin. Fluctuations in RH can strain the adhesive emulsion, causing the gelatin to expand and contract. The strain from incorrect RH can also cause the emulsion to crack or separate along the plates' edges. [10]
The sunny 16 rule can be used in varying light by setting the shutter speed nearest to the ISO film speed and f-number according to a generalized exposure table, as: [3] [4] Tessina with exposure guide plate from the 1960s. At that time, DIN 21 was equivalent to ASA 80. After 1983, DIN 21 was ASA 100. [5]
This template is a cut-down instance of the more general {{Google custom}} template. You may wish to make similar templates if you need to create repetitive links to other portions of Wikipedia that {{Google custom}} can search. This saves much typing compared to using {{Google custom}} for each link.
Exposures may be pushed by increasing the time in the first bath, pulled by reducing the time in the first bath, with an adjustment of approximately 25% for a one-step change. 2 Wash 2:30: 100 ± 1 °F (37.8 ± 0.6 °C) Rinse with running water, change water after 30 seconds, or extend rinsing time if necessary. 3 Color developer (CD) Bath 2 6 to 8