Talk:Light gun

List of games
we need to make a list page of all the light gun games. theres a light gun games category as well.. the list is getting much too long, also is it possible for a light gun to work with a pc monitor? --larsinio 03:14, 16 October 2005 (UTC)


 * it is possible to get a light-gun to work with a PC monitor (CRT only) - not sure if anyone has developed one. Y control 16:18, 27 April 2006 (UTC)

Non CRT detection
So I've been to the arcade and played TimeCrisis/House of the Dead which uses a rear-projection screen. Does this mean that where I thought it was using LCD rear-projection I am mistaken; or is there another method for shooting games? Please help I'm stumped. Y control 16:18, 27 April 2006 (UTC)
 * I beleive LCD displays now exist that can refresh quickly enough for light guns to work. In arcades, if the gun is fixed to a platform, it's most likely positional. Last time I saw House of the Dead though, it used freely-movable light guns. What makes you think it was using a LCD rear-projector rather than a CRT one? boffy_b 17:06, 26 August 2006 (UTC)

This should be more clearly stated in the article
...But if I try to add anything, it would just receive those citation needed tags and revertion. — Preceding unsigned comment added by 80.221.132.209 (talk) 20:01, 7 January 2012 (UTC)

HotD and HotD2 used CRT monitors. But HotD2/3/4 used gun sensors around the monitor (12 total). This technology is not like conventional light gun/pen systems.

Also, the screen is not projection, it is mirrored. JamesRTwine (talk) 03:51, 11 March 2021 (UTC)


 * partially wrong. 10 sensors. Also there are projection versions of hotd2,3 probably 4. 67.219.76.39 (talk) 00:16, 5 August 2023 (UTC)

Time Crisis 3 doesnt use any of the listed methods
The light gun of Time Crisis 3 knows where it is with no blacking/brightening of the screen or IR sensors. This can be seen on calibration where the crosshair follows the aim around the screen cointinuously with no triggering/flashing. I would guess that because the gun intercepts the video signal with a cable, it recognizes the TVs location with an internal camera. —Preceding unsigned comment added by 64.40.59.113 (talk • contribs)
 * You are mistaken. TC3 uses the GunCon 2, which works by measuring the time delay between a sync pulse sent to the controller and the pulse received from the photodiode. This is why the calibration screen is needed. Shinobu 03:39, 9 March 2007 (UTC)
 * In other words, this is what the article calls "cathode ray timing". As long as a pixel isn't completely black or completely red, the photodiode in a CRT gun can compare the timing of the flickering of the blue and green phosphors to the timing of the video signal. What 64.40.59.113 describes is more like how a pentop computer works. --Damian Yerrick (talk | stalk) 04:52, 9 March 2007 (UTC)
 * @cathode ray timing: correct. As for the Fly pen, I've taken a look at the web page, and frankly, it was really sad. It always is when companies try to be cool and end up horribly overdoing it. And couldn't they have thought up a better name? "I brought my Fly." *sniff* On the technological side, it "sees" it's position with a LED-based solution. So I guess it works much like an optical mouse does. Remember how recently someone modded a cheap optical mouse to work like a small (18 by 18 pixels) B&W scanner? Also, it says on the website you need special paper, so I guess it reads some kind of pattern of the paper, probably Anoto, and it (edit: read article) with the Anoto pattern, which the pen uses to establisch it's absolute position, rather than just inferring relative positions like a mouse does. But basically, the technologies seem very similar. Shinobu 15:14, 11 April 2007 (UTC)

Operation Wolf
Operation Wolf was removed as an example of an arcade game using a positional gun, with the claim that it used an optical gun. According to KLOV.com Operation Wolf always used a positional gun, and I recommend adding it back as it is such a popular game. It revitalized interest in shooting-style arcade games, showing that a scrolling field could work in a gun-based game after Nintendo's forgettable Gumshoe. User:Dj ansi 21:16, 14 May 2006 (UTC)


 * That's correct Operation Wolf (arcade version) used a positional gun; not sure why it was removed. I think the home versions may have used light-guns where available. Y control 10:07, 22 May 2006 (UTC)


 * How could the first light gun be in 1936?? Their weren't even computers, the first computer came in WWII. Vincentsc 16:10, 6 June 2006 (UTC)


 * Go to a carnival and play the light gun based target range.

Added modern, IR based, methods (method three) --83.54.140.19 11:24, 9 June 2006 (UTC)


 * I understand it, it wasn't a computergame, I thought so, but okay, I understand. Vincentsc 10:52, 10 June 2006 (UTC)

light gun in fps games?
a light gun should be used in fps games, it would make it easier, have a analog stick to move forward and backward and side to side, a trigger, and a scope button, and other commands like enter exit, jump, reload, etc, make a light gun that plugs into a ps3 controller or xbox 360 controller and play fps games like battlefield: bad company with extremely accurate aiming. —The preceding unsigned comment was added by Superchad (talk • contribs).
 * PS3? Xbox 360? Conspicuous by its absence in your comment is the one next generation console that comes out of the box with a light gun controller that uses IR and accelerometers. Wii have what you want. --Damian Yerrick (☎) 01:22, 7 October 2006 (UTC)

More pictures!
There have been some wacky lightgun designs over the years (notably the Menacer and Super Scope); it would be nice to see a wider spread of images beyond two Nintendo products. Kelvingreen 09:12, 10 October 2006 (UTC)

Terminator 2: Judgment Day
I thought the arcade version of Terminator 2: Judgment Day used the positional setup. Dread Lord CyberSkull ✎☠ 00:40, 22 February 2007 (UTC)

SNES Superscope cathode ray timing
The SNES Superscope doesn't work quite as described. The article implies that the scope determines where it is aiming based on a timing signal from the SNES, and then transmits the coordinates to the SNES. In actuality, the Scope simply transmits the "I see an excited phosphor!" signal over pin #6 of the connector, which is connected to a pin on the PPU2 chip inside the console. Since this chip is also doing the pixel output, it simply 'latches' the current pixel row and column when the pin makes a 1 to 0 transition.

The major difference is that the Scope doesn't need any kind of timing signal from the console at all, and in fact if you look at the architecture of the console the only regular timing signal is a 60 Hz button-state poll. I've described this in more detail over at the Superscope talk page. Anomie 02:54, 14 April 2007 (UTC)

More elaborate?

 * "The second method, used by the Super Nintendo Entertainment System's Super Scope and computer light pens is more elaborate but more accurate."

I actually think the first method (cycling through the targets) sounds more elaborate, but maybe that's just me. David 16:53, 19 July 2007 (UTC)

is it worth mentioning that the Wiimote actually uses a ccd sensor?
should it be mentioned that the Wiimote instead of simple sensors actually has a digital camera in its tip? (afaik no one has figured out how to get the captured image from the camera, all that can be obtained are the x and y coordintaes of up to 4 ir brightspots)--TiagoTiago 01:23, 22 September 2007 (UTC)
 * It should if you can cite a source. --Damian Yerrick (talk | stalk) 16:58, 22 September 2007 (UTC)

ACT Labs gun?
The article makes no mention of the USB lightgun ACT Labs produce for PC use. s this notable enough for inclusion? Chris Cunningham (not at work) - talk 20:41, 7 February 2008 (UTC)
 * It should be if you can cite a reliable source. --Damian Yerrick (talk | stalk) 00:16, 8 February 2008 (UTC)


 * Here are some to consider:, , , etc. Best, --  Le Grand Roi des Citrouilles  Tally-ho! 00:36, 8 February 2008 (UTC)

blank?
what happened to this page needs urgent repair. —Preceding unsigned comment added by 121.219.104.202 (talk) 10:09, 10 May 2008 (UTC)

use of weapon vs firearm
Weapon is a non-specific term meaning a device used for combat or military i.e. hurting people. firearm is more specific and does not carry a specific combat meaning. While a firearm can be used as a weapon (military rifle) it can also be used for sport (target shooting). N9wxu (talk) 06:02, 3 January 2009 (UTC)

pink/orange Justifier is cross platform
There was only one type of pink/orange Justifier that plugded into both a blue SNES Justifier or a blue Genesis Justifier. —Preceding unsigned comment added by 75.111.33.136 (talk) 04:20, 9 May 2010 (UTC)

Comparison of positional gun to an analog stick
Very few analog sticks can rotate the way a positional gun can.--Asher196 (talk) 04:08, 3 April 2011 (UTC)
 * Yes, but the article does not equate them with traditional analog sticks. Rather, it compares them in terms of functionality and to that end it is accurate; a positional gun is a form of analog controller. It's odd that this article has a section dedicated to them, but it is preferable to a small article. --Jtalledo (talk) 14:30, 15 June 2012 (UTC)

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Light beam gunnery is not just for video games, but also a serious sport.
There are pro-match grade light rifles, fitted with battery powered xenon lamps, which are used instead of compressed air rifles for indoor 10-meter precision shooting clubs e.g. at schools. They almost perfectly imitate the size and weight and wood / steel build of cal. 4.5mm / 0.177" professional air rifles. They are used with full-torso support garment for steadier aiming, as if olympic sport. Seem to be popular in Japan, likely due to the lack of noise issues and reduced risk of injury. There is even an ongoing anime / manga series devoted to them, called "Rifle is Beautiful". 80.99.111.252 (talk) 10:30, 18 October 2019 (UTC)

Inappropriate citation required.
Why is "The light gun and its ancestor the light pen are now rarely used as pointing devices due largely to the popularity of the mouse and changes in monitor display technology—conventional light guns work only with CRT monitors" marked as needing a citation when the claim in substantiated by the content of the "Design" section? JamesRTwine (talk) 03:56, 11 March 2021 (UTC)

Uncited material in need of citations
I am moving the following uncited material here until it can be properly supported with inline citations of reliable, secondary sources, per WP:V, WP:CS, WP:IRS, WP:PSTS, WP:BLP, WP:NOR, et al. This diff shows where it was in the article. Nightscream (talk) 18:52, 10 February 2022 (UTC)

LEAD SECTION
Modern screen-based light guns work by building an optical sensor into the gun, which receives its input from the light emitted by on-screen target(s). The first device of this type, the light pen, was used on the MIT Whirlwind computer.

The light gun and its ancestor the light pen are now rarely used as pointing devices due largely to the popularity of the mouse and changes in monitor display technology—conventional light guns work only with CRT monitors.

Early history
These early light gun games, like modern laser tag, used small targets (usually moving) onto which a light-sensing tube was mounted; the player used a gun (usually a rifle) that emitted a beam of light when the trigger was pulled. If the beam struck the target, a "hit" was scored.

Use in video games
The video game light gun is typically modeled on a ballistic weapon (usually a pistol) and is used for targeting objects on a video screen. With force feedback, the light gun can also simulate the recoil of the weapon. The first gun for a home console was in fact a big rifle, the Magnavox Odyssey's Shooting Gallery, which looked very lifelike and even needed to be "cocked" after each shot.

Light guns are very popular in arcade games, but had not caught on as well in the home video game console market until after the Nintendo Entertainment System (NES), Sega Master System (SMS), Mega Drive/Genesis, Super Nintendo Entertainment System (SNES) systems and Atari XEGS. Many home 'Pong' systems of the 1970s included a pistol or gun for shooting simple targets on screen. Nintendo's NES Zapper for the NES is the most popular example of the light gun, and Duck Hunt its most popular game.

Traditional light guns cannot be used on LCD and plasma screens, and they have problems with projection screens.

There are also light guns for Sega Saturn, PlayStation and several other console and arcade systems. Recent light gun video games include Resident Evil: The Umbrella Chronicles, Time Crisis 4, Virtua Cop 3, and The House of the Dead: Overkill.

In 2007, Nintendo released the Wii Zapper for the Wii, a peripheral which is actually a plastic shell that houses both the Wii Remote and nunchuk for gun-style video games. While it does not contain any traditional light gun technology, the peripheral makes use of the Wii Remote's built-in infrared tracking system to shoot targets that correspond on-screen. Its name is a reference to the classic NES Zapper for the Nintendo Entertainment System. Sony has also released attachments that house the PlayStation Move motion controller in the form of a pistol and rifle, the latter named the Sharp Shooter.

Namco's GunCon 3 also uses an infrared optical sensor system similar to the Wii Remote.

Design
The "light gun" is named because it uses light as its method of detecting where on screen the user is targeting. The name leads one to believe that the gun itself emits a beam of light, but in fact most light guns actually receive light through a photodiode in the gun barrel.

There are two versions of this technique that are commonly used, but the concept is the same: when the trigger of the gun is pulled, the screen is blanked out to black, and the diode begins reception. All or part of the screen is painted white in a way that allows the computer to judge where the gun is pointing, based on when the diode detects light. The user of the light gun notices little or nothing, because the period in which the screen is blank is usually only a fraction of a second (see persistence of vision).

Cathode ray timing
The second method, used by the Super Nintendo Entertainment System's Super Scope and computer light pens, is more elaborate and more accurate.

The trick to this method lies in the nature of the cathode ray tube inside the video monitor (CRTs were the only affordable TV monitors in the late 1980s and early 1990s, when this method was popularized). The screen is drawn by a scanning electron beam that travels across the screen starting at the top until it hits the end, and then moves down to update the next line. This is done repeatedly until the entire screen is drawn, and appears instantaneous to the human eye as it is done very quickly.

When the player pulls the trigger, the computer (often assisted by the display circuitry) times how long it takes the electron beam to excite the phosphor at the location at which the gun is pointed. The light gun sends a signal after sensing the sudden small change in brightness of a point on the screen when the electron gun refreshes that spot. The computer then calculates the targeted position based on the monitor's horizontal refresh rate (the fixed amount of time it takes the beam to get from the left to right side of the screen). Either the computer provides a time base for the horizontal refresh rate through the controller's connector (as in the Super Scope), or the gun reads the composite video signal through a T-connector on the A/V cable (as in the GunCon 2). Once the computer knows where the gun is pointed, it can tell through collision detection if it coincides with the target or not.

Many guns of this type (including the Super Scope) ignore red light, as red phosphors have a much slower rate of decay than green or blue phosphors. As a result, some games brighten the entire screen's green and blue pixels somewhat when the trigger is pulled in order to get a more reliable fix on the position.

Display timing is not possible with plasma, LCD, and DLP monitors, since they do not have an "off" state between refreshes. Their digital signal processing electronics also may introduce a nontrivial lag between the signal input and display output, which is not predictable because it varies between monitor models and brands and even between mode settings of a single monitor. A lag which is not very significant for player feedback may be enough to completely destroy the accuracy of a display-timing based light gun system.

Infrared emitters
A new method was developed to compensate for display technologies other than CRT. It relies on one or several infrared light emitters placed near the screen, and one IR sensor on the muzzle of the gun. When the trigger is pressed, the gun sends the intensity of the IR beam it detects. Since this intensity depends upon both distance and relative angle to the screen, angle sensors are located in the gun. This way a trigonometric equation system is solved, and the muzzle's 3D position relative to the screen is calculated. Then, by projecting the muzzle on the screen with the measured angles the impact point is determined. An early example of this technology (though not using IR) can be seen in the NES Power Glove Accessory, which used three ultrasonic sensors serving the same function as the IR emitters used in some lightguns.

A simpler variant is commonly used in arcades, where there are no angle detectors but 4 IR sensors. However, this can prove inaccurate when shooting from certain distances and angles, since the calculation of angles and 3D position has a larger margin of error.

Other variants include three or more emitters with different infrared wavelengths and the same number of sensors. With this method and proper calibration three or more relative angles are obtained, thus not needing angle detectors to position the gun.

Sometimes, the sensors are placed around the screen and the emitter on the gun, but calculations are similar.

...and modern arcade light gun games.

The additional IR image processing results in lag or "cursor drift", i.e. when quickly sweeping the light gun across the screen the crosshair will seem to drag slightly behind where the light gun is actually pointing.

Image capture
When the user pulls the trigger the screen is replaced for a split-second with a seemingly random display of black and white pixels, or blocks of pixels. The light gun contains a fine-resolution but low pixel count digital camera with a very narrow field of view. The gun converts the small image into a binary array which allows the computer to locate the exact position the gun was pointed at. This method is compatible with any screen of any size. The size of the screen and distance to shooter is entered into the gun driver software to determine the dimensions of the random blocks/pixels to best allow rendering on the light gun CCD.

Rectangular positioning
The light from the LCD TV or screen is used as reference point. Optionally, a thin rectangular border can be added to the display content, for games with a dark graphics theme.

An advantage of this method is that the size and distortion of the rectangle screen outline can also be used to determine the position and angle of the gun relative to the screen. Theoretically this can be used to create a 3D tunnel effect, by moving the gun around the screen to hide behind scenery or peek around corners.

Multiplayer
A game that uses more than one gun reads both triggers continuously and then, when one player pulls a gun's trigger, the game reads that gun until it knows which object was hit.

"Poorly designed games" is unjustified judgement of value
Greetings, fellows.

Regarding the following paragraph: "A side effect of this is that on poorly designed games, often a player can point the gun at a light bulb or other bright light source, pull the trigger, and cause the system to falsely detect a hit on the first target every time. Better games account for this either by detecting if all targets appear to match or by displaying a black screen and verifying that no targets match."

I don't think "poorly designed" is good wording here. This is technology; solving these problems may seem obvious in hindsight but it certainly required a lot of creativity, and these techniques might well have beeb patented.

But even if it weren't, to call a whole game "poorly designed" because it didn't take into account how players might cheat in single player sounds very excessive.

I think I have made my point.

Best regards, ~victorsouza (talk) 12:41, 16 May 2022 (UTC)