échelle d’ouverture de diaphragme
/eʃˈɛl duvɛʁtˈyʁ də- djafʁˈaɡm/
n
English: lens aperture scale · 光圈刻度
Sens：Graduated scale that controls the diaphragm’s opening; it is measured in f-stops and a high f-stop indicates a small opening.
English: lens aperture scale · 光圈刻度