Why are red dots red?

[Reloadron]

First of all you can get dots in any color you want as can be plainly seen:



Now looking back at the original post maybe some clarifications are in order:

Why are red dots red?
Just curious as to why Aimpoint and EOTech optics are always 'red dots'. For comparison if a green laser is much more visible compared to a red laser based on the way our eyes perceive color, why don't they have Green Dots sights?

I know there's some cheap red dots that allow you to change the colors but that always seemed more like a gimmick than a feature.

When we look at Aimpoint for example and look at what Aimpoint has to say:

Worldwide leader and originator of red dot sights also called reflex sights.
Aimpoint® is the recognized worldwide leader and originator of the red dot sighting technology.

That Reflex part is important.

A red dot sight is a common classification[1] for a type of non-magnifying reflector (or reflex) sight for firearms that gives the user an aimpoint in the form of an illuminated red dot. A standard design uses a red light-emitting diode (LED) at the focus of collimating optics which generates a dot style illuminated reticle that stays in alignment with the weapon the sight is attached to regardless of eye position (nearly parallax free). They are considered to be fast acquisition and easy to use gun sights for target shooting, hunting, and in police and military applications.

Note at this point there is no mention of a LASER, only the lowly LED (Light Emitting Diode). The LED is merely a light source within the optics. The above quote was taken from here. The link is worth a read to understand how these animals work. Why Red? Considering that a Red, Green. Blue or Yellow LED have little difference in cost (the common red is less expensive) a Red LED does have less current draw on the battery and considering most optics like this use small coin cell batteries my guess is battery life is a prime consideration.

LASER sighting systems are a totally different animal. LASER systems actually project a beam of light on the target, just like LASER pointers. Movie makers love these things. The bad guy looking down as a LASER dot sits on his body freaks them out. Pretty cool as where that spot is will be the point of impact of the bullet. Not that you can see a LASER spot between your eyes but you get the idea.

Today's red low power LASER beams are created by LASER diodes not to be confused LEDs which are different animals. Red LASER diodes are cheap, green LASER diodes are not so cheap. It becomes a matter of how the light is created. I gave a link in an earlier post covering that.

Anyway, red dot scopes as we call them are not LASER optics. Aimpoint optics do not use a LASER system. They use a red LED as a light source. The most logical for the choice of red is likely battery life in my opinion. Beyond current draw colors other than red, orange and yellow typically have higher working voltages adding to battery configuration problems.

Just My Take
Ron

 

[benEzra]

Just to clarify, the Eotech uses a red diode laser and a diffraction grating to create a hologram of a red ring and diffraction-limited center dot in the window. The Aimpoint and other dot-type reflex sights use LED's, as described.

 

[JustinJ]

Anyway, red dot scopes as we call them are not LASER optics. Aimpoint optics do not use a LASER system. They use a red LED as a light source. The most logical for the choice of red is likely battery life in my opinion. Beyond current draw colors other than red, orange and yellow typically have higher working voltages adding to battery configuration problems.

That's not actually completely true. The Eotech, per the link I posted, does actually use a laser to create a holographic image for use as a reticle.

I wonder though if part of the reason red is so commonly used in red dot scopes does not have to do with the fact that laser sighting systems were all also initially red. Really though I think it probably has most to do with the ability of the eye to quickly pick up red against most commonly encountered targets.

 

[JohnBT]

Somebody's eye, not mine. Red sux.

 

[-v-]

Always assumed its because red diodes and lasers use the least power out of the spectrum, thus giving these weapon sights the longest possible battery life.

 

[e3mrk]

Because it has a Red Light.

 

[Reloadron]

Just to clarify, the Eotech uses a red diode laser and a diffraction grating to create a hologram of a red ring and diffraction-limited center dot in the window. The Aimpoint and other dot-type reflex sights use LED's, as described.

My bad as I only focused on Aimpoint. Thank you all for pointing out Eotech uses a different method using a LASER.

Thanks
Ron