Traditional Culture Encyclopedia - Photography major - What does SLR EV mean?

What does SLR EV mean?

EV, the abbreviation of Exposure Values, is a quantity that reflects the degree of exposure. Initially defined as: the sensitivity is ISO 100, the aperture coefficient is F 1, and when the exposure time is 1 s, the exposure is defined as 0, and the exposure is reduced by one step (the shutter time is halved or the aperture is reduced by one step), and the EV+ 1. Increase exposure by one step (double shutter time or increase aperture by one step), EV- 1.