ENGLISH
REFERENCE

ISO

n. C / U
C1 Advanced iso Informal Vulgar

n. a setting on a camera that controls how sensitive it is to light. You use a higher number when it is dark, but it can make your photos look grainy.

n. the sensitivity of a camera's sensor or film to light, expressed as a numerical value. Higher values allow for faster shutter speeds in low light but introduce digital noise or grain.


SIMPLE

I had to increase the ISO because the room was very dark.

CONTEXTUAL

When shooting the night sky, you should use a high ISO and a tripod to capture the stars clearly.

COMPLEX

Modern full-frame sensors can handle a high ISO with minimal noise, allowing photographers to capture candid moments in dimly lit environments without the need for an external flash.

Origin

Officially from Greek ίσος (ísos, “equal”). However, a participant in the initial meetings disputes this etymology, claiming that the link to ίσος was decided on after the name ISO was set.

Usage

Often treated as uncountable when referring to the general setting, but countable when referring to specific values (e.g., 'an ISO of 800').

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