Infrared Torches and Film

[Guest georgehare]

Saw a while back that people were talking about infrared torches etc to help with night vision sights, just found this thought it might bo of an interest. 6x6inch of film - £15.

 

Hope it might help.

 

George

[Poacher]

It might help if you tell us where you saw it

[pin]

Posted the same kind of thing, bit thicker for £10 delivered a while back I think.

 

Tis true all you need is a light source and some IR pass filter material, tried it with a 12led torch and some black film neg the other night and it worked a treat. 20x20 sheet from another place on the way after xmas, then the 3mil candle power torch is getting a 5mm replacement cover fitted

[Poacher]

Pin, if putting more IR out there dramatically improves the performance i.e you can see more, then whats the improvement in Gen2/3 (is it just image quality?)

[pin]

Tried it with the two gen1 monoculars I have (newton and bresser).

 

The thing is it probably won't matter at all which NV you use, any IR light will do the same job regardless of make of NV.

 

The problem comes from having too strong a source of light, be it IR or otherwise, too close to the NV device.

 

I am sure when I have the 3mil torch (cheapy £10 thing with a 55w car headlamp and 12v battery in it) I will have to be extremely careful where I am pointing it.

 

With any NV you need to be extremely careful with the light that reaches it, even if you can't see it (IR) it will still damage the NV if you show too much of it..

 

My plan was to have the torch out ahead of the NV pointing away..

 

Actually, with gen2 (and some premium gen1 stuff) they will trip off when too much light reaches them - the problem is if the source is strong enough (headlamp) at close range (<10 m) unless the device has an iris which can cut off the light, it will be damaged.

[Poacher]

I see what your saying, but if you can improve the performance of a Gen1 simply by putting more IR out there, what are the improvements that the manufacturers have made in Gen2/3 ?

[pin]

Very complex answer, but essentially A LOT

 

The "gen" bit in NV speak refers to the grade of the "tube".

 

Essentially NV kit is only as good as the tube on which it is based.

 

Shamelessly lifted from another site :-

 

"Every nightvision device (NV) works on the principle of multiplying the brightness of the image in the wavelength of visible and near-visible infrared light. The unit contains an objective lens, light amplification tube with the high voltage power supply, and the eye -glass. Light (starlight for example) reflects from the object to be viewed, passes though the objective lens and creates an image on the photo cathode of the light amplification tube. Inside of the light amplification tube, the light is electronically amplified and projected as a yellowish green glow on a screen that is then seen by the viewer. The two most important characteristics for the NV are the characteristics of the NV tube and optics of the unit. Internationally accepted terminology classifies the NV tubes in I, II, or III generation (with certain intermediate levels of I+ and II+ gen.). "

 

The higher grade the tube the more sensitive it is to light, and therefore the more you can see.

 

To improve a gen1 scope's light gathering capability you reflect more light off the thing you want to see. Same for the others, including higher grade. However, the "resolution" of the picture you can see starts to become a factor as the distance you can "see" becomes greater.

 

Gen3 tubes of military grade will allow you to recognise facial features of a subject at 200yds like you would see through a normal scope in daylight, with little more than starlight. Gen1 tubes with more light (IR) simply don't have the resolution in the tube (detail) to let you see in detail. You can see things like trees further away, but anything you wanted to see in detail you simply wouldn't be able too. Much like looking at a blurred photo, no matter how much you squint you can't make it better.

[Poacher]

Cheers still debating on getting one of those from lidl for use on when lamping (as a searching tool).. The rabbits down my way are very jumpy, enter a field during daylight and their all gone, I need a tool that'll give me some oneupmanship

[pin]

Find someone close to you and try one, you won't be upset

[pin]

Depends on the torch really.

 

With the bresser NV only I can see rabbit to about 100yds, I have not seen fox with it yet, but they have better reflectivity in the back of their eyes so I would say it would be further.

 

With any NV the background makes a difference. If you are looking towards houses with lights, street lights or roads then it will be overwhelmed with the light and be no use to you.

 

With a dark background and more powerfull IR, just like a more powerful regular lamp, you will see the eyes further out. You will only see the eyes though. The resolution of gen1 kit isn't sufficent to see detail past 60-70 yards.