focal-plane shutter

19 LETTERS · STARTS WITH F

focal-plane shutter is a valid 19-letter word worth 27 points in Scrabble and 32 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

F4O1C3A1L1-0P3L1A1N1E1S1H4U1T1T1E1R1

4 + 1 + 3 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 1 + 0 + 1 + 4 + 1 + 1 + 1 + 1 + 1 =27 PTS

DOUBLE WORD → 54TRIPLE WORD → 81

MEANING

What does focal-plane shutter mean?