How Duck Hunt for the NES worked without a sensor bar

[ManaMan]

Just recently picked up a Wii U for my daughter's birthday. Picked up a few games for mom (Yoshi's Wooly world, work out games) and dad (Xenoblade) too.

We had a friend over for dinner and my daughter was showing her a level she made on Mario Maker. The level was classic Mario. This got is talking about old NES games and Duck Hunt in particular. Our friend pointed at the sensor and said "how did they get it to work without a sensor?? Was technology actually better back then?". We theorized for several minutes on how this could work before I remembered I have Google in my pocket that can answer these sorts of questions.

From Mental Floss: When you pressed the trigger button on the gun the screen would go completely black for a moment except for the duck which would show up as white pixels. The gun barrel had a very basic photo sensor that could tell if it was pointed at white pixels or black pixels. If it was pointed at white, you got the duck. Black, your missed. Pretty clever actually. You'd never notice the screen flash black... Or if you did, it'd be just part of the gun shot effect.

[Julius Seeker]

Yeah, it's a light gun, so al of the interactivity is based on colours of light; some of the more sophisticated guns would calibrate based on the settings of your TV, like the SNES Super Scope - it made it more difficult to cheat. The Wii remote used 2 different techs depending on its purpose, a third with WM+.

1. Infrared - Interacted with the sensor bar to put an IR pointer on the TV screen; this is used with UI, shooting pointers, strategy/sim controls etc... Examples are the Wii menu, RE4, Super Mario Galaxy, Scarface.
2. The accelerometers - Took into account velocity and direction, which was used to great success in several different motion related games: examples Wii Sports and Just Dance.
3. Gyroscope - tracked motion through 3D space, and it would use the IR as a reference point to calibrate from time to time, but otherwise functioned independently. This is the tech that was incorporated into the Wii Motion+ and was used in the later Tiger Woods Golf games and Legend of Zelda Skyward Sword.

[Zeus]

Yeah, relatively primitive but effective.

The Namco guns for PS2 worked differently. They plugged into the video out port on the RCA cables and actually project an (upside) image inside the gun (I think it was a reflector or something, can't exactly remember). That's why it was so fast and accurate.