noun
flashgun; external flash unit
Refers to a portable flash device used in photography, typically mounted on a camera or used off-camera. Common in both amateur and professional contexts.
暗い室内ではフラッシュガンを使うと、写真が明るく撮れます。
In a dark room, using a flashgun lets you take brighter photos.
彼は新しい
He attached a new flashgun to his camera.