Film speed
What is film speed? Film speed is a measure of a photographic film’s sensitivity to light. It is expressed as an ISO number and determines the film’s ability to capture …
Photography Terminology
Mirror Lock-up
Mirror lock-up is a feature found on some SLR camera models that allows the user to lock the mirror, which is located in front of the sensor or film, in …
Reciprocity failure
Reciprocity failure, also called the Schwarzschild effect, is the term used to describe photographic film’s non-linear response to low light exposure. What it means is that once the light levels reaching the film drop below a certain threshold, the effective sensitivity of the emulsion decreases.