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What kind of lense do I need to see infrared with my eyes? Answered

What kind of lense do I need to see infrared with my eyes?
I want to take pictures and see inrared with my eyes through a lense or filter of some sort.

What kind of filter do you recomend?

Can I see IR with a IR filter? (def. of a filter: blocks certain wavelenghts of light).




Best Answer 8 years ago

Your eyes cannot register IR.  It is a physical impossibility.

You need a camera that will detect IR and convert it to visible wavelengths.

I believe some types of night vision goggle do this.

> Your eyes cannot register IR. It is a physical impossibility.

Here's an old paper where human IR sensitivity is measured from 400nM out to 1000nM

Sensitivity of human eye to infra-red radiation
JOSA, Vol. 37, Issue 7, pp. 546-553 (1947)

A diagram from the above paper, semi-log graph

Note that the sensitivity decreases smoothly, with no division between "visible" and "IR." Vision at 1000nM is almost 13 log units down from the green sensitivity peak at ~550nM

A digital camera will see IR.
You can see IR in the camera view screen.

Thanks people!!!

This is a great community.
I liked all the different answers!
All the best to you!

IR is a wavelength - our eyes are not sensitive to IR (this is not the same as near-IR visible light)

There is FILTER that can convert IR to something visible.  There is an instructable on how to make goggles that filters 99% of visible light and all you're left with is very very low red, and 'infrared' - which you still cannot see.

To truly see infrared you need something like an IR camera (or one modified to take IR photos) then look at the picture/video coming from that sensor.

 You may be thinking of the Infrared Goggles project, which uses filters that block out most of what we usually consider to be visible light.

Because of the way our classification works, most people will use the term "infrared" for wavelengths of light bigger than 700 nm.

Because of the way your vision works, there is no hard cut-off point between "visible wavelengths" and "invisible wavelengths" of light. Rather, your retinal pigments have a wavelength at which they work best and rapidly lose sensitivity as you move away from this point.

So it may be possible to see a tiny bit into the range usually classified as infrared by making this light very very intense and blocking out all other light. This is what the Infrared Goggles project attempts to do.

However, it only works as advertised when everything is lit by a very powerful source of near-infrared (such as the Sun). It may help you notice things you would ordinarily overlook. But it absolutely will not give you night vision or enable your eyes to receive any light that they don't normally receive.


 One more thing- digital cameras usually have a built-in "IR filter". This filter is actually intended to block infrared light and let only visible light through. Without a good IR-blocking filter, your camera would pick up infrared. (You can see this spillover by turning out the lights and pointing a cheap camera or cell phone at a hot electric burner or at the end of a TV remote control. Blue or purple glare may show up.)

There are instructions for swapping out the IR-blocking filter for one that passes only IR light. You need a digital camera or two that you don't mind accidentally destroying.



8 years ago

Many black and white video cameras, like cheap security cameras, see very well in the IR spectrum. I suppose a web cam might, although I haven't tried.. Remember, you will need an IR light source. Night vision goggles are not (normally)  IR, but they are ampifiers. The point, if you point an IR camera out into the dark, you will see a lot of dark. The unamplified IR given off by a living body is dang near invisible.
IR LEDs can make a good "invisible" flood light for short distances, 3 or 4 meters, to watch things or take pictures with, and animals (people too) cant see it....

With your eyes? By definition, IR is the band just below the red we can see, so the answer is "forget it".

With other tools? Many digital cameras can see at least some IR bands. There have been instructables about ways to take advantage of that via a filter that blocks most visible light. If you already have a camera on hand, that's worth trying.

While Kiteman is totally correct, you can pretend with things like those appearing on this page, righthand side under where you are.