frb
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Post count: 1327

Not sure about the white bar but the other markings (1-18) on the black ring is probably the Exposure Value – a standard measure of light intensity. A change in EV of 1 equates to 1 stop (that is why you change exposure compensation by 1 EV)

An EV of 15 = sunny 16 (1/125, f16.0, 100 ISO) and an EV of 1 = 4 sec, f2.8, ISO 100