It is pretty evident why people ask me if the flash impedes the field of vision in a plane.
Well, certainly, there is something new in your field of vision, but the obstacle is probably much, much smaller than you imagine. If you have a compass on top of your instrument panel, the flash sort of hides behind it.
The picture to the right is taken in Holger Backs LS10 (CEO at DG Flugzeugbau), camera held at the pilot's eyes position. Just the upper edge of the CFRP-boat is visible at all.
You may test this easily by your own. Fetch a piece of card-board and cut it to the size 6 * 16 cm and plug it into your cockpit instead of the boat.