n.
Pronunciation: ' ī -s ə - ˌ f ō t
Function: noun
Etymology: International Scientific Vocabulary is- + -phote (fr. Greek ph ō t-, ph ō s light) ― more at FANCY
Date: circa 1909
: a curve on a chart joining points of equal light intensity from a given source
– iso · phot · al \ ˌ ī -s ə - ' f ō -t ə l \ adjective