Do Passive Night Vision Scopes Exist Without Electronic Amplification?

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In summary, most binoculars that are marketed as 'night vision devices' have large apertures and either use electronic amplification to increase light gathering or have a large entrance pupil to allow more light in.
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fleem
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Has anyone ever created a monocular (or binocular) for the main purpose of simply gathering more light without much, if any, telephoto effect? A cursory google of it shows me nothing. I guess I'm surprised there aren't old WW2 surplus "passive night vision systems" out there that are simply lens systems held to the eye but that have a huge objective lens with hardly any telephoto capability, in order to work with moonlight, twilight, man-made ambient light, or even starlight. (Note: I did find a so-called "passive" system that still uses electronic amplification of visible light--I'm not sure why it was called passive, then!)
 
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Most of them do! Just turn off / cover up the illuminator (with something that's IR opaque, like aluminum foil).

If you mean completely passive, light gathering devices, they've had them since at least World War II: night glasses (or night glass binoculars). Large aperture glasses (can't make them too big, otherwise they aren't portable or you won't be able to resolve anything), sometimes issued with atropine eye drops to dilate the pupils and allow more light to enter the eyes (beyond what normal night vision gives you):
http://en.wikipedia.org/wiki/Night_vision#Night_glasses

They're still sold:
http://www.beststuff.com/fromthewire/deutsche-optik-introduces-new-night-glass-binoculars.html
 
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  • #3
MATLABdude said:
Most of them do! Just turn off / cover up the illuminator (with something that's IR opaque, like aluminum foil).

If you mean completely passive, light gathering devices, they've had them since at least World War II: night glasses (or night glass binoculars). Large aperture glasses (can't make them too big, otherwise they aren't portable or you won't be able to resolve anything), sometimes issued with atropine eye drops to dilate the pupils and allow more light to enter the eyes (beyond what normal night vision gives you):
http://en.wikipedia.org/wiki/Night_vision#Night_glasses

They're still sold:
http://www.beststuff.com/fromthewire/deutsche-optik-introduces-new-night-glass-binoculars.html

Awesome! Thanks for the help :)
 
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  • #4
fleem said:
Has anyone ever created a monocular (or binocular) for the main purpose of simply gathering more light without much, if any, telephoto effect? A cursory google of it shows me nothing. I guess I'm surprised there aren't old WW2 surplus "passive night vision systems" out there that are simply lens systems held to the eye but that have a huge objective lens with hardly any telephoto capability, in order to work with moonlight, twilight, man-made ambient light, or even starlight. (Note: I did find a so-called "passive" system that still uses electronic amplification of visible light--I'm not sure why it was called passive, then!)

Not sure what you mean by 'passive' amplification, other than simply having a large entrance pupil: most binolculars fufill that purpose.

'night vision' goggles, and there are several technologies, are usually powered- there is some amplification provided electronically (for example, microchannel plates). I think these are called 'passive' since they do not illuminate the scene. 'Active' systems generally illuminate the scene somehow, and there may be an amplified imager to detect.

Does that help?
 

1. What is a passive night vision scope?

A passive night vision scope is a device that uses ambient light, such as moonlight or starlight, to enhance the visibility of objects in low light or darkness. It does not emit any light of its own, making it less detectable than active night vision technology.

2. How does a passive night vision scope work?

A passive night vision scope collects ambient light through its objective lens and amplifies it using an image intensifier tube. The amplified light is then converted into an image that can be seen through the eyepiece. The image appears green because the intensifier tube converts all light into green, which is the most sensitive color to the human eye in low light conditions.

3. What are the advantages of using a passive night vision scope?

The main advantage of using a passive night vision scope is its ability to provide clear vision without emitting any light. This makes it less likely to be detected by others and can be useful for covert operations. Additionally, passive night vision scopes do not require batteries or external power sources, making them more reliable and cost-effective.

4. Are there any limitations to using a passive night vision scope?

One limitation of passive night vision scopes is that they are not effective in complete darkness. They require at least some ambient light to function properly, so they may not be suitable for use in heavily wooded or underground areas. Additionally, passive night vision scopes have a limited range compared to active night vision technology.

5. Can a passive night vision scope be used during the day?

No, passive night vision scopes are designed specifically for use in low light or darkness. Using them during the day can damage the image intensifier tube and may result in permanent damage to the device. It is important to only use a passive night vision scope when there is enough ambient light available to provide a clear image.

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