Visable - spectrum night vision
- Thread starter dean1818
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Glenn E. Meyer
New member
810 nm is over the very high end of the visible spectrum. Usually that is said to cut off at 750 nm. I don't know the bandwidth that the gadet puts out, so if it is center a 810 but puts out some in the 700s with enough energy - you might see it.
Also, some studies report visual sensations up to 1000 nm. It's really an empirical question for the specific gadget and would also depend on distance from the source.
Also, some studies report visual sensations up to 1000 nm. It's really an empirical question for the specific gadget and would also depend on distance from the source.
Double Naught Spy
New member
810 nm produces a light that cannot be seen in terms of shine, but you can certainly see the red glow from the source. Virtually all IR lights emit light either side of their claimed nm (as Glenn noted) unless they are very high end or filtered lights.
So the illuminator can be seen with the naked eye and it may actually broadcast visible light several inches. You can see the cherry glow of most non-military 900-950 nm IR lights as well. Often, you have to be looking directly at the light to see it or notice it.
If you are thinking of using it for hunting, then yes, the hogs and predators can see the cherry glow from it. Some ignore it and some will get spooked if they see it, especially if they have been hunted that way before.
810nm is a good compromise between the really visible 700nm red lights and the nearly invisible 950+nm lights. The compromise is that you can see the glow, but you get no visible shine at distance and you get good distance.
For the same amount of power/brightness, the higher your nm, the shorter the useful range of the light. Also, much of the higher end IR light does not work well with Gen 1 NV and may not work well with some digital NV. So 810nm is a reasonable illuminator with broad applications.
If you are thinking for tactical home defense considerations, then you don't want anything below 900nm (and you probably want higher) if you want to be "invisible" to others.
Make sense?
So the illuminator can be seen with the naked eye and it may actually broadcast visible light several inches. You can see the cherry glow of most non-military 900-950 nm IR lights as well. Often, you have to be looking directly at the light to see it or notice it.
If you are thinking of using it for hunting, then yes, the hogs and predators can see the cherry glow from it. Some ignore it and some will get spooked if they see it, especially if they have been hunted that way before.
810nm is a good compromise between the really visible 700nm red lights and the nearly invisible 950+nm lights. The compromise is that you can see the glow, but you get no visible shine at distance and you get good distance.
For the same amount of power/brightness, the higher your nm, the shorter the useful range of the light. Also, much of the higher end IR light does not work well with Gen 1 NV and may not work well with some digital NV. So 810nm is a reasonable illuminator with broad applications.
If you are thinking for tactical home defense considerations, then you don't want anything below 900nm (and you probably want higher) if you want to be "invisible" to others.
Make sense?
Having worked in total, & I mean total darkness for many years let me share a little.
We used IR illuminators for low light cameras as photographic film is "blind" to all IR, except for a few special emulsions specifically designed for it. After a couple of hours in the total darkness of a film darkroom (no orange lights, that's a Hollywood thing for paper darkrooms.) We could see not only most of the IREDs, but could actually tell different models apart.
Most of the 750's were easy to spot, because they had "spill" into other wavelengths, but the German-made 850's were darn near impossible because they had a much tighter cutoff for visible radiation.
Its not just the main frequency, but the cutoff in dB that is additive here. You'd need to read & understand a spec sheet for the emissions of the individual source.
We used IR illuminators for low light cameras as photographic film is "blind" to all IR, except for a few special emulsions specifically designed for it. After a couple of hours in the total darkness of a film darkroom (no orange lights, that's a Hollywood thing for paper darkrooms.) We could see not only most of the IREDs, but could actually tell different models apart.
Most of the 750's were easy to spot, because they had "spill" into other wavelengths, but the German-made 850's were darn near impossible because they had a much tighter cutoff for visible radiation.
Its not just the main frequency, but the cutoff in dB that is additive here. You'd need to read & understand a spec sheet for the emissions of the individual source.