candid (adj.)

1620s, "white, bright," from Latin candidum "white; pure; sincere, honest, upright," from candere "to shine," from PIE root *kand- "to shine." In English, metaphoric extension to "frank, honest, sincere" first recorded 1670s (compare French candide "open, frank, ingenuous, sincere"). Of photography, "unposed, informal" 1929. Related: Candidly; candidness.