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reflex red dot sight
Posted: Sun Aug 30, 2009 1:47 am
by raptorforce
how do these work-diagrams are helpful.... and would it be possible to make one?if so how?
this kind of sight:
http://images.google.com/imgres?imgurl= ... 6sa%3DN%26
um%3D1
its the 5 one from the top
Posted: Sun Aug 30, 2009 2:08 am
by FORE!!!!
Its a holigraphic sight the dot appears in the view window when looked at from the right angle, no dot is placed on the target,so you wont give urself up..
EDIT : it also has 4 different holographic images to choose from
Posted: Sun Aug 30, 2009 2:18 am
by raptorforce
FORE!!!! wrote:Its a holigraphic sight the dot appears in the view window when looked at from the right angle, no dot is placed on the target,so you wont give urself up..
EDIT : it also has 4 different holographic images to choose from
ok i know all that i was more intrested in how to make one and how does it project a dot without the light just passing straight through the window
Posted: Sun Aug 30, 2009 3:09 am
by Willdebeers
Because it projects it from the side.
Posted: Sun Aug 30, 2009 6:23 am
by FORE!!!!
raptorforce wrote:FORE!!!! wrote:Its a holigraphic sight the dot appears in the view window when looked at from the right angle, no dot is placed on the target,so you wont give urself up..
EDIT : it also has 4 different holographic images to choose from
ok i know all that i was more intrested in how to make one and how does it project a dot without the light just passing straight through the window
lol i dont think you really understand by your answer, but seriously dude give up im very doubtfull you will be able to build one of these,with the amout of time effort and money you would spend on it ,i dont think its really worth it...but who am i,,prove me wrong

Posted: Mon Aug 31, 2009 1:24 am
by raptorforce
FORE!!!! wrote:raptorforce wrote:FORE!!!! wrote:Its a holigraphic sight the dot appears in the view window when looked at from the right angle, no dot is placed on the target,so you wont give urself up..
EDIT : it also has 4 different holographic images to choose from
ok i know all that i was more intrested in how to make one and how does it project a dot without the light just passing straight through the window
lol i dont think you really understand by your answer, but seriously dude give up im very doubtfull you will be able to build one of these,with the amout of time effort and money you would spend on it ,i dont think its really worth it...but who am i,,prove me wrong

someone did on youtube...its not on of those fake ones it really works
youtube>"homemade red dot sight" and its one of them on the first page
Posted: Mon Aug 31, 2009 10:34 am
by geardog32
if you are really wanting to build one yourself, go to a gun show and buy a cheap one(or order one online). then take it apart.

Posted: Mon Aug 31, 2009 3:40 pm
by jimmy101
I doubt you can make one for as cheap as just buying one. Unless you already have a laser and the optics ...
Shop around some more. I've seen the low end Red Dots for less than $30 at places like Kmart or Miejers.
Posted: Mon Aug 31, 2009 5:24 pm
by raptorforce
geardog32 wrote:if you are really wanting to build one yourself, go to a gun show and buy a cheap one(or order one online). then take it apart.

then that defeat the purpose of building one if i already own a complete one
im gonna try get one from my friend
Posted: Mon Aug 31, 2009 6:00 pm
by FORE!!!!
and i sussed out those videos on youtube,they all looked like ghetto pieces of shit,and the film quality is that poor it stresses me trying to watch it
can i ask why exactly you need this,or that particular one?
or was it just a project you were looking to do?
Posted: Mon Aug 31, 2009 11:43 pm
by kozak6
As I understand it, there is an LED which faces away from your eye. Somewhere forward of it, there is a lens. The lens has a coating so that it reflects the light from the LED back towards your eye. You line the reflection of the LED up in the center of the lens, and that's it. Some of these types of sight have a crosshair or other marking on the lens to make it easier to line up.
It doesn't seem like it would be hard to make something similar. However, it would be significantly harder to make a good one.
Posted: Mon Aug 31, 2009 11:59 pm
by Technician1002
kozak6 wrote:As I understand it, there is an LED which faces away from your eye. Somewhere forward of it, there is a lens. The lens has a coating so that it reflects the light from the LED back towards your eye. You line the reflection of the LED up in the center of the lens, and that's it. Some of these types of sight have a crosshair or other marking on the lens to make it easier to line up.
It doesn't seem like it would be hard to make something similar. However, it would be significantly harder to make a good one.
You understood part of it. Normaly the light is at a right angle to the axisis of the scope and the scope has a glass at an angle inside so as you look through the scope, the red dot from the LED is superimposed on the field of view.
What seperates the good scopes is the focus of the spot. Idealy you want the spot to appear as it is on your target. To do this, a lens is required to make the light source appear distant, so it focuses the same aparrant distance as the target. This extra optics is what makes a good scope better than a cheap one.
This projection of a virtual image of the spot at a far distance in the same plane as the target makes a good scope.
http://www.bullseyepistol.com/dotsight.htm Note this uses the angled lens to make the virtual spot appear far.
http://en.wikipedia.org/wiki/Virtual_image