Infared Light Not Visible, BUT still visible???

LED Flashlights – General Info
1

Hi to the respected, experienced members

I was hoping to ask for some advice please.

If an infra red flashlight emits light that is not visible to the naked eye, then why is it that with a night vision device, the intruder or animal being observed can still see that the infrared light is switched on (most of the time). There are a small number of night vision devices where it is not visible to the intruder being watched at night.

My reason for asking this is that I saw this reasonably priced night vision device with a separate infra red flash light attached to the device underneath. It is called

Aliynet Spotting Scope 20-60x60mm, Night Vision Goggles

The link at amazon is below:

https://www.amazon.com/dp/B07J1XZ66P/ref=emc_b_5_t

But the seller does not tell us if this would be visible to the naked eye from the perspective of an intruder detecting that he is being observed whilst on the farm at night.

So I thought if I buy this and it disappoints me, then perhaps I can buy a different infra red flashlight to use in it's place, but then I must be sure it will not be visible.

Is there anyone who might know which infra red thrower flash lights would not be visible to an intruder being observed?

Then if I may ask, do you think it will extend the range of this device (which is not too bad at 400 metres/437 yards for the price) if I were to buy a powerful infra red thrower?

Finally, do you think this device is actually not really a 60x zoom, but more of a digital zoom that is relying on one's mobile phone, considering the price ? They might be trying to trick an unsuspecting person like myself (I know there are technically inclined, highly knowledgable bright sparks here who can pick this up very quickly

Therefore I thank you all for your advice and help on this matter.

Thank you

Regards

Peter

2

My security cam uses IR lights after it detects movement using passive IR.

I can see the active IR lights as dim red lights.

It all depends on the wavelength of the IR.

3

That’s an interesting scope,
The reviewers seem to be really happy with the results at least the scope.
Fake spot is A, reviewmeta is 3.8, I guess not bad

I wonder if it all seems too good to be true.
I thought Night vision means you can use it complete darkness. None of the pictures seem to be depicting that.

I am no expert but the images seem to be staged.

Look at the rabbit, The light shines on the rabbit’s back from above maybe an angle but more like a moonlight and not like a headlight or flashlight beam upfront .
Not even close to how it supposed to look at night.

So based on the pictures, it doesn’t seem to be anywhere near what it claims.
I wonder why do you need install an app to see the video?

I hear you , not easy to get something affordable for 400+ yards, Thats lot to cover but IR frequency is a pretty long wave so maybe there is a thrower that will reach that far. Most IR bulbs emit some visible light that could be filtered out with IR filter, even something like a piece of old exposed dark film.

If you want to know what the “intruder” could detect, I think cell phone cameras have no IR filter so you will see it on cell phone at least “live”. Digital cameras have an IR filter so you wont see the IR light on the images.

4

I took a look at the Amazon light.
I think you will be disappointed if you get it.
I don’t know about the IR light source. But one reviewer said it’s bright.
But good Night Vision at that price range is questionable.
They don’t say anything about resolution. Something has to digitize the image to transmit to a phone.
If it’s super low res, it won’t be very satisfactory.

And look at the lighting on the rabbit shot. It’s the same damn image, only one is converted to B&W.
Clearly BOGUS.

It might also just be a low light camera that uses “IR” as a light source. To boost a super high ISO.

Check out some YouTube videos on Night Vision Scopes and see what the output really looks like.
If you do give it a try, give us a report.

All the Best,
Jeff

5

I”m suspicious of that illustration, the night mode has the same shadow as the day mode, illumination from off to the side — not from the camera’s point of view.
I suspect Photoshop not a real image.

6

It is obviously the exact same image, just converted to black and white.

This is IR, illuminated by IR LEDs on the camera.

[Album] imgur.com
7

Hat tip to Caramba, who first pointed out the fake nighttime image in an earlier comment.

8

A little help image wise…

9

I am truly blessed to be in the company of such bright people here!

Thank you to zltwo, caramba, jeff51, and hank because the seller would have tricked me with that photo etc.

But Caramba, what I actually meant is that if one stands on one's farm at night and sees someone jump over the fence with this camera, then would their eyes spot the infra red flash light beneath the scope, but you were saying one must cover the infr red flash light with an old exposed dark film.

I saw a filter that filters above 850nm, then I found this statement:

"All cameras are most sensitive to 850nm infra-red, delivering superior surveillance footage at night. 940nm delivers virtually invisible covert lighting but does result in reduced performance (typically up to 40% less) and requires a very sensitive camera".

Jeff51 you said it is likely a low light camera that uses “IR” as a light source to boost a super high ISO.

Does anyone know of any reasonably priced infra red throwers, considering import taxes?

Finally, if I may ask, do you think this can function as a day scope as well, or do you think this 60X zoom is just another scam?

Then again, as you pointed out, it seems to have reasonably good reviews, but maybe the buyers were like me (don't know what to look out for).

My understanding of 60x zoom means if something is 6000 metres away, then the size of the image would appear as if it is 100 metres away. I wonder if this is the case with this device.

Once again, thank you to all the brilliant members here for the excellent advice they always give me.

Regards

Peter

10

Just a final thought. If an intruder is not yet alerted by the tiny red dot of your IR-light, he (sorry: he/she) certainly will be running like hell for looking at your full face in the light emitted by the smartphone.

11

Hi Henk4U2

You have a good point there, but remember the smart phone's light can be dimmed and blue light set.

Also remember that there is wifi on this device, so the "night vision" device can be outside pointing at the fence while one is inside the house 30 metres away (they claim a range of 30 metres).

Now this device claims 400 metres, and if one is behind some bush, then they might see the infra red light easier than the blue light from the phone (of course one could also duck behind the tree while only the night vision device is exposed).

But a point aside to all the experienced members here. It seems instead of buying an infra red flashlight thrower, it will be cheaper to simply buy an infra red filter to place over my flashlight which has a reasonable throw well beyond 400 metres.

What do all the respected, experienced, members think?

Thank you again

Regards

Peter

12

If these is such a thing as a good IR filter, I would go for an IR flashlight.
With an IR flashlight, the IR filter (if it works) would only have to surpress part of the emitted light.
With a normal flashlight, the IR filter would have to surpress almost ALL of the emitted light.
That is like chopping down a tree because you want to stick something between your teeth.

13

With old incandescent flashlights a filter (i.e. something that blocks visible light but not infrared) will work to some extent because a large amount of the output is actually infrared in a wide spread of wavelengths, so their visible light efficiency is very low, that’s way they are not used anymore.

LEDs don’t emit enough near infrared for a filter to be useful.

14

Go to ebay/amazon and search for 720nm infrared pass filter, you can buy a cheap one as optical quality is not needed.

Depending on the power being shoved through it you might see a small amount (very dim) of red, then go up to 760nm, or just get the 760nm first.

However you can just get a 760nm ir led, no white (or red) in that :wink:

Your biggest problem is to throw infrared that far as 5w is the most powerful I have seen, and that uses 4 led in one small package, 10w and over are arrays, difficult to get them to a tight focus.

Cheers David

15

Is the objective to get video footage of someone trespassing? A dedicated outdoor security camera would likely do a better job of that.

I think motion activated area lights, or even a handheld light being a deterrent would be a better option though unless there’s some specific reason you want this trespasser to think nobody knows they’re there?

16

What is situation that you are dealing with?

What do you hope to accomplish?

What light do you have that you want to put an IR filter on?

17

Just noticed that they actually do list the camera resolution. 1080p.
The picture of the army guys is also photoshopped. The camera and tripod are an add in.

Yes a 60x scope is about 600m seen at 10m. BUT - I question the ability of any cheap scope to have useful magnifications at 60x. Even in bright sunlight.

Here is a guy who reviews surveillance cameras and systems.
This video looks at a 25X POE PZT Camera.
That thing from Amazon won’t hold a candle to this system (I believe).

About 8m in he shows off what a quality system could do.

Or if you just want to record what’s going on for later retrieval. There are trail Cams that have total blockout filters that don’t admit any visable light.

But – Are the intruders going to have any type of night vision Eq?

Perhaps what you are really after is a rifle scope with night vision. You will pay a dear price for a good one.

Some more random videos that you may find usefull.

All the Best,
Jeff

18

Hi Jeff51, XXO, BurningPlayd0h, pommie and ggf31416

Thank you to you all and everyone else for the excellent advice.

The objective is to find reasonably priced night vision device and preferably not visible to the intruder (I have found one American made device on Amazon that claims to not be visible to the intruder ie. the infra red light from the device) and with zoom capability.

The farm is huge, huge.

I was scammed last night. I would like to ask some advice from Jeff51 and all the other experienced, kind, bright sparks here, and Jeff last time advised me to use a new thread (and thank you Jeff for all the kind links).

My flashlight is a Haikelite MT40, just received and also giving problems.

I will post the new thread,

Thank you to everyone again.

Regards

Peter

19

I doubt that you are going to find anything cheap that is going to work at 1000M - even if you find something with enough magnification and a IR light source, such as an IR laser, capable of reaching out that far, your field of view is going to be very small and your resolution is going to be poor.

You would probably be better off with hidden IR game cameras that can send alerts/stream video to your phone when they detect motion. If you are concerned about visible glow of the IR light source, get one around 880 nm or above. Keep in mind that anyone with a night vision device can see your IR light source – even a cell phone camera may be able to detect it.

20

You might do better getting a couple of dogs and fencing the property.