JoeHeugh
Super member
Tomorrow I will be picking up a half decent "red dot sight" that I intend playing with over summer to evaluate it's effectiveness as a hunting tool. Having spent some time with a cheapie I had a good look through the various types on show at the NSS (blugh) and the one I liked really rather surprised me, lets just say it's not one I would have picked from a catalogue but it was love at first sight! I'll let you know what it is sometime later when I've had a chance to play with it... Anyway I embarked a on a bit of research, much as I did with the Night Vision Story, and here we are, a nice short summary for you 
Don't ask me about the Thermal Story, I'm getting there but (blugh again) and the NV one needs updating too (ugh).
The Red Dot Story.
The purpose of a red dot sight is simple, to allow the shooter to engage short range static or moving targets as quickly as possible by keeping both eyes open and having the target “on sight” as the gun is raised. They are not intended for precision or long range styles of shooting and for air gunners are probably best suited for plinking with pistols or rifles but I believe they also have a place in the modern hunters armoury. Also, and to be pedantic, with all the variations available the term red dot doesn’t really mean anything anymore but it does serve as a useful shorthand for one of the four technologies the shooter has to chose from:
Occluded Eye Gunsight aka the Singlepoint, the earliest red dot, still in military use but now obsolete for civilian applications. Dot size 6 moa or more.
Reflex Sights. The most common form of red dot available in either open or tubed format with reticles ranging from a simple dot to more complicated patterns in multiple colours. Dot size down to 2 moa but usually more.
Holographic Sights aka Eotechs. With a reticle formed by a holographic image the dot can be as small as 1 moa and does not increase when a magnifier is used. As a magnifier can be quickly flipped in and out of place this makes for a most adaptable sighting system giving quick target acquisition without the magnifier and longer range precision shooting with it in place. Dot size 1 moa
(Micro) Prism Sights. These are in effect small telescopic sights with an etched reticle that will work without power. They do not use a laser and do not need a reflective window allowing the clearest view through the sight. As they are awkward to use with magnifiers they are also available in various magnifications from 1 to 6 with the larger models best exemplified by the Trijicon ACOG. Dot size down to 2 moa but often 3.
Although red dots can be very effective there are provisos. First there are the idiosyncrasies of our eyes, astigmatism can turn the dot into an unusable starburst while eye dominance can cause difficulties or an uncomfortable experience and ideally it will be the dominant eye that looks through the scope. Shooting with both eyes open can be unnatural for many but it is the only way to benefit from a red dot and in some respects you have to retrain your brain and that means practice, it is a different way of shooting and it takes time to get right and for some it won’t go well.
The other problem with red dots is the vast majority are of the reflex type and there are huge number of cheap Chinese clones that are mediocre at best. Build quality of these clones has improved over the years but parallax issues remain. Although all red dots are advertised as virtually parallax free none truly are and it is noticeable as the dot moves towards the edge of the window, Aimpoint and Eotech use proprietary technology to minimise the effect with their sights and the other high end makers probably do the same but with many others it’s very much hit and miss, you pays yer money etc and as most shooters will try one of the cheaper options first before giving up the red dots reputation has suffered.
Occluded Eye Gunsight (OEG)
This was the original red dot and is often generically referred to as the Singlepoint after the original early 1970’s made in Britain Normark model. It works by producing a red dot on a black background in the eyepiece which is then superimposed by the brain over the target when shooting with both eyes open. They can only be used for snap shooting as the dot starts to drift if looked at for any length of time and there is also the issue of the size of the dot is generally 6 moa or more as it is dependent on the width of the light pipe for effective brightness. However with practice they work well in their intended role and are capable of rapidly hitting man size targets out to 200 yards. Because they must be used quickly they require a different mentality, most shooters will make the final decision to pull the trigger after a quick assessment with the rifle raised, with these sights the decision should be made beforehand.
OEG’s are intended to be extremely robust for military use and ready at all times with the lightsource being provided by fibre optic supplemented in some models with tritium to avoid the use of batteries. The Singlepoint was first used in action by American Special Forces in Vietnam and was carried unofficially by British troops in Northern Ireland. It was also sold on the civilian market with many finding their way on to air rifles and although they became a bit of a must have they were not much use for anything more than a bit of plinking, their main limitation being a lack of precision due the size of the dot. It’s futuristic appearance also led to it being chosen to sit on weapons in Star Wars making them popular with collectors and inflating the value of original examples.
The sights were first produced by Normark in Britain, then transferred to Armson in South Africa they moved to America. Armson OEG's remains in production with one being popular model on grenade launchers while modern and retro models are still available for rifles and pistols. Chinese copies with various degrees of functionality are also available for Star Wars collectors.
Reflex Sights
The original “electric dot scope” where the dot is formed by laser light reflected back to the eye by a transparent window was the Oxford Lightning Illuminated Gunsight marketed without success in 1968. However it achieved some favour with shooters and the idea was taken up by Aimpoint in 1973. Many other companies now produce their own versions and the market is awash with cheap Chinese copies but Aimpoint still reign supreme. I would say that over 90% of all red dot sights on the market today are of the reflex type. One limitation in the early days was battery life but this is now much improved and with “shake awake” a red dot can be left on and stored for long periods without much concern about dead batteries.
One of the problems with the reflex type is that the dot must be visible against all backgrounds leading to frequent changes of brightness and the need for reflective and dimming or polarising coatings on the window marginally reducing visibility, however as we are using both eyes it is only necessary to be able to make out the target through the window as this will anchor the dot and prevent the drift common with the OEG types.
Reflex sights come in two formats, the open windowed type which can be made very small and is very popular on pistols and as a back up scope mounted sight and the more robust closed tubed type better suited to a rifle. This has led to some confusion with some being called red dots and others described as reflex depending on who you are talking to but they all work the same way and they are all reflex sights.
Laser emitters are no longer limited to producing a simple red dot and now project various reticle shapes and different colored emitters such as red and green are often incorporated in the same device. As a rule of thumb I would avoid too many of these features as unless done to a very high standard each emitter will have a different point of aim so again expect to pay a decent amount for your sight or keep your expectations at the plinking level and accept that a cheap sight that will give a lot of fun on a CO2 pistol will not be the best on a hunting rifle.
Holographic Sights
The first holographic sight was the 1996 Bushnell Holo Sight which was actually manufactured by a small company called Eotech who have since become the main supplier of these sights. The only other supplier today is Vortex, don’t be fooled, there are no Chinese clones or any other makes of holographic sight, any that purport to be are just a reflex sight in a fancy dress.
These sights work by bouncing a laser from a holographic plate and projecting the image through the scope. Complex reticles are possible and a 3d reticle has even been produced however Eotech have used pretty much the same simple dot in a circle design for over 20 years. One unusual aspect of the holographic reticle is that being projected into space the dot does not increase in size when a magnifier is used making it ideal for military or hunting applications when a longer range precision shot is called for.
Holographic sights are extremely robust and come in a distinctive and quite bulky format with a large window protected by a shield within a shield, they are intended for rifles and are too large for pistols. Their adoption by military forces and subsequent reputation in video games has made them very desirable leading to the multitude of Chinese lookalikes we see today, so buyer beware, if it’s not a genuine Eotech or Vortex it’s not a holo sight.
Prism Sights
Telescopic prism sights have been in use for over a century. Rather than rely solely on lenses to create the image they use prisms to fold the lightpath and shorten the overall length of the instrument in the same way binoculars do. Modern prism scopes use roof prisms and are capable of giving excellent images that are flat across the field of view and give excellent eye relief with the most famous being the ACOG series produced byTrijicon from 1987. As well as normal aiming the ACOG was intended to accommodate the Bindon aiming concept, that is aiming with both eyes open just like a red dot. I’ll just say here that all the ACOG clones on Ebay etc are just normal non prism scopes and optically offer none of the benefits at the cost of extremely short eye relief. Micro prism “red dot” scopes use the same system to produce a 1 power or more telescopic sight with an etched reticle in a small format that can be used in much the same way as a standard red dot sight. They are often sold on the fact that because the dot is not laser generated astigmatism is not a problem and assuming the astigmatism is not bad enough to interfere with everyday life this is true. However there are two other key benefits, as an etched reticle is used the sight can still be used when the battery dies or against a bright background without adjustment and as no reflective coating is needed the lens optical quality is not compromised giving the best view possible through the eyepiece. There is one downside and it is because these are “normal” telescopic sights the reticle must be focused to the users eye with a diopter adjustment, this is a key identification feature of a prism scope and is not an issue if the sight is used on it’s own as it’s set and forget but if a magnifier is used then it will probably have to be adjusted between the users eye and the magnifier as it is switched in and out. Vortex consider the user having to do this a bodge and have stated in their catalogues that prism scopes cannot be used with magnifiers but do admit this is incorrect, they just don’t want their users buying into an inconvenience and are actually working on a way round it.
Because of the problem with magnifiers prism sights are themselves available in various magnifications but I would advise caution and a try before you buy approach. The whole point of the red dot is the both eyes open approach and dealing with a different magnification in each eye can be difficult. This might force some users to close one eye and if that happens it may be better to consider an LPVO if you need that extra magnification as at the moment there are no adjustable magnification micro prisms.
Magnifiers
A magnifier is basically a prism scope (without reticle) that sits behind the red dot to magnify the image for better long range shooting. They can be used with both eyes but I suspect that most users will use them in much the same way they would a normal telescopic sight. As the rifle is expected to be used mostly for short range rapid fire the magnifier is hinged to one side to be snapped in place when needed. This brings an extra consideration, the red dot on it’s own can be placed anywhere on the rifle to suit the user but it is now the shorter eye relief of the magnifier that sets it’s location. A bigger consideration is the fact that the magnifier will increase the size of the dot as much as the image so while the target might be easier to see there will be no improvement in shot placement. As noted above, magnifiers are really intended to be used with holographic sights where the dot is not magnified and using one with any other type is really a bit of a bodge that might not work for you. Again if that’s the case then you might be better off with an LPVO.
Don't ask me about the Thermal Story, I'm getting there but (blugh again) and the NV one needs updating too (ugh).The Red Dot Story.
The purpose of a red dot sight is simple, to allow the shooter to engage short range static or moving targets as quickly as possible by keeping both eyes open and having the target “on sight” as the gun is raised. They are not intended for precision or long range styles of shooting and for air gunners are probably best suited for plinking with pistols or rifles but I believe they also have a place in the modern hunters armoury. Also, and to be pedantic, with all the variations available the term red dot doesn’t really mean anything anymore but it does serve as a useful shorthand for one of the four technologies the shooter has to chose from:
Occluded Eye Gunsight aka the Singlepoint, the earliest red dot, still in military use but now obsolete for civilian applications. Dot size 6 moa or more.
Reflex Sights. The most common form of red dot available in either open or tubed format with reticles ranging from a simple dot to more complicated patterns in multiple colours. Dot size down to 2 moa but usually more.
Holographic Sights aka Eotechs. With a reticle formed by a holographic image the dot can be as small as 1 moa and does not increase when a magnifier is used. As a magnifier can be quickly flipped in and out of place this makes for a most adaptable sighting system giving quick target acquisition without the magnifier and longer range precision shooting with it in place. Dot size 1 moa
(Micro) Prism Sights. These are in effect small telescopic sights with an etched reticle that will work without power. They do not use a laser and do not need a reflective window allowing the clearest view through the sight. As they are awkward to use with magnifiers they are also available in various magnifications from 1 to 6 with the larger models best exemplified by the Trijicon ACOG. Dot size down to 2 moa but often 3.
Although red dots can be very effective there are provisos. First there are the idiosyncrasies of our eyes, astigmatism can turn the dot into an unusable starburst while eye dominance can cause difficulties or an uncomfortable experience and ideally it will be the dominant eye that looks through the scope. Shooting with both eyes open can be unnatural for many but it is the only way to benefit from a red dot and in some respects you have to retrain your brain and that means practice, it is a different way of shooting and it takes time to get right and for some it won’t go well.
The other problem with red dots is the vast majority are of the reflex type and there are huge number of cheap Chinese clones that are mediocre at best. Build quality of these clones has improved over the years but parallax issues remain. Although all red dots are advertised as virtually parallax free none truly are and it is noticeable as the dot moves towards the edge of the window, Aimpoint and Eotech use proprietary technology to minimise the effect with their sights and the other high end makers probably do the same but with many others it’s very much hit and miss, you pays yer money etc and as most shooters will try one of the cheaper options first before giving up the red dots reputation has suffered.
Occluded Eye Gunsight (OEG)
This was the original red dot and is often generically referred to as the Singlepoint after the original early 1970’s made in Britain Normark model. It works by producing a red dot on a black background in the eyepiece which is then superimposed by the brain over the target when shooting with both eyes open. They can only be used for snap shooting as the dot starts to drift if looked at for any length of time and there is also the issue of the size of the dot is generally 6 moa or more as it is dependent on the width of the light pipe for effective brightness. However with practice they work well in their intended role and are capable of rapidly hitting man size targets out to 200 yards. Because they must be used quickly they require a different mentality, most shooters will make the final decision to pull the trigger after a quick assessment with the rifle raised, with these sights the decision should be made beforehand.
OEG’s are intended to be extremely robust for military use and ready at all times with the lightsource being provided by fibre optic supplemented in some models with tritium to avoid the use of batteries. The Singlepoint was first used in action by American Special Forces in Vietnam and was carried unofficially by British troops in Northern Ireland. It was also sold on the civilian market with many finding their way on to air rifles and although they became a bit of a must have they were not much use for anything more than a bit of plinking, their main limitation being a lack of precision due the size of the dot. It’s futuristic appearance also led to it being chosen to sit on weapons in Star Wars making them popular with collectors and inflating the value of original examples.
The sights were first produced by Normark in Britain, then transferred to Armson in South Africa they moved to America. Armson OEG's remains in production with one being popular model on grenade launchers while modern and retro models are still available for rifles and pistols. Chinese copies with various degrees of functionality are also available for Star Wars collectors.
Reflex Sights
The original “electric dot scope” where the dot is formed by laser light reflected back to the eye by a transparent window was the Oxford Lightning Illuminated Gunsight marketed without success in 1968. However it achieved some favour with shooters and the idea was taken up by Aimpoint in 1973. Many other companies now produce their own versions and the market is awash with cheap Chinese copies but Aimpoint still reign supreme. I would say that over 90% of all red dot sights on the market today are of the reflex type. One limitation in the early days was battery life but this is now much improved and with “shake awake” a red dot can be left on and stored for long periods without much concern about dead batteries.
One of the problems with the reflex type is that the dot must be visible against all backgrounds leading to frequent changes of brightness and the need for reflective and dimming or polarising coatings on the window marginally reducing visibility, however as we are using both eyes it is only necessary to be able to make out the target through the window as this will anchor the dot and prevent the drift common with the OEG types.
Reflex sights come in two formats, the open windowed type which can be made very small and is very popular on pistols and as a back up scope mounted sight and the more robust closed tubed type better suited to a rifle. This has led to some confusion with some being called red dots and others described as reflex depending on who you are talking to but they all work the same way and they are all reflex sights.
Laser emitters are no longer limited to producing a simple red dot and now project various reticle shapes and different colored emitters such as red and green are often incorporated in the same device. As a rule of thumb I would avoid too many of these features as unless done to a very high standard each emitter will have a different point of aim so again expect to pay a decent amount for your sight or keep your expectations at the plinking level and accept that a cheap sight that will give a lot of fun on a CO2 pistol will not be the best on a hunting rifle.
Holographic Sights
The first holographic sight was the 1996 Bushnell Holo Sight which was actually manufactured by a small company called Eotech who have since become the main supplier of these sights. The only other supplier today is Vortex, don’t be fooled, there are no Chinese clones or any other makes of holographic sight, any that purport to be are just a reflex sight in a fancy dress.
These sights work by bouncing a laser from a holographic plate and projecting the image through the scope. Complex reticles are possible and a 3d reticle has even been produced however Eotech have used pretty much the same simple dot in a circle design for over 20 years. One unusual aspect of the holographic reticle is that being projected into space the dot does not increase in size when a magnifier is used making it ideal for military or hunting applications when a longer range precision shot is called for.
Holographic sights are extremely robust and come in a distinctive and quite bulky format with a large window protected by a shield within a shield, they are intended for rifles and are too large for pistols. Their adoption by military forces and subsequent reputation in video games has made them very desirable leading to the multitude of Chinese lookalikes we see today, so buyer beware, if it’s not a genuine Eotech or Vortex it’s not a holo sight.
Prism Sights
Telescopic prism sights have been in use for over a century. Rather than rely solely on lenses to create the image they use prisms to fold the lightpath and shorten the overall length of the instrument in the same way binoculars do. Modern prism scopes use roof prisms and are capable of giving excellent images that are flat across the field of view and give excellent eye relief with the most famous being the ACOG series produced byTrijicon from 1987. As well as normal aiming the ACOG was intended to accommodate the Bindon aiming concept, that is aiming with both eyes open just like a red dot. I’ll just say here that all the ACOG clones on Ebay etc are just normal non prism scopes and optically offer none of the benefits at the cost of extremely short eye relief. Micro prism “red dot” scopes use the same system to produce a 1 power or more telescopic sight with an etched reticle in a small format that can be used in much the same way as a standard red dot sight. They are often sold on the fact that because the dot is not laser generated astigmatism is not a problem and assuming the astigmatism is not bad enough to interfere with everyday life this is true. However there are two other key benefits, as an etched reticle is used the sight can still be used when the battery dies or against a bright background without adjustment and as no reflective coating is needed the lens optical quality is not compromised giving the best view possible through the eyepiece. There is one downside and it is because these are “normal” telescopic sights the reticle must be focused to the users eye with a diopter adjustment, this is a key identification feature of a prism scope and is not an issue if the sight is used on it’s own as it’s set and forget but if a magnifier is used then it will probably have to be adjusted between the users eye and the magnifier as it is switched in and out. Vortex consider the user having to do this a bodge and have stated in their catalogues that prism scopes cannot be used with magnifiers but do admit this is incorrect, they just don’t want their users buying into an inconvenience and are actually working on a way round it.
Because of the problem with magnifiers prism sights are themselves available in various magnifications but I would advise caution and a try before you buy approach. The whole point of the red dot is the both eyes open approach and dealing with a different magnification in each eye can be difficult. This might force some users to close one eye and if that happens it may be better to consider an LPVO if you need that extra magnification as at the moment there are no adjustable magnification micro prisms.
Magnifiers
A magnifier is basically a prism scope (without reticle) that sits behind the red dot to magnify the image for better long range shooting. They can be used with both eyes but I suspect that most users will use them in much the same way they would a normal telescopic sight. As the rifle is expected to be used mostly for short range rapid fire the magnifier is hinged to one side to be snapped in place when needed. This brings an extra consideration, the red dot on it’s own can be placed anywhere on the rifle to suit the user but it is now the shorter eye relief of the magnifier that sets it’s location. A bigger consideration is the fact that the magnifier will increase the size of the dot as much as the image so while the target might be easier to see there will be no improvement in shot placement. As noted above, magnifiers are really intended to be used with holographic sights where the dot is not magnified and using one with any other type is really a bit of a bodge that might not work for you. Again if that’s the case then you might be better off with an LPVO.
