Thermal and preparedness.

[BrianS]

Both thermal and NV aren't in the budget to get both at once, but which one is better to start with? Budget would be 3-4K for each.

 

[wilcam47]

Both thermal and NV aren't in the budget to get both at once, but which one is better to start with? Budget would be 3-4K for each.

If i had choice, id go thermal first

 

[wilcam47]

But guess it depends what you are using it for

 

[steves1911]

Both thermal and NV aren't in the budget to get both at once, but which one is better to start with? Budget would be 3-4K for each.

Thermal...it won't give you the identification at range that a good NV will but guaranteed it will detect things you would have never noticed with just NV. Thermal works In daylight too.

 

[BrianS]

Thermal...it won't give you the identification at range that a good NV will but guaranteed it will detect things you would have never noticed with just NV. Thermal works In daylight too.

Good point. I'll head down the rabbit hole of information and try to narrow down the pile of thermal options.

 

[teratos]

Thermal...it won't give you the identification at range that a good NV will but guaranteed it will detect things you would have never noticed with just NV. Thermal works In daylight too.

Yep.

 

[Archeryrob]

Got mine today. Only got to mess with it for a few min but pretty cool for the cost. At about 80 yards up the driveway I could still make out most things. It doesn't appear to look through windows well. Had to go outside because all I kept seeing looking through the window was a black screen.

InfraRed wave lengths bounce off of glass.

 

[smokey]

Both thermal and NV aren't in the budget to get both at once, but which one is better to start with? Budget would be 3-4K for each.

Do you want to move around at night(nightvision) or detect warm-blooded things(thermal)? Those are the jobs each does.

 

[gwchem]

InfraRed wave lengths bounce off of glass.

Technically, only a fraction bounce off, the amount determined by the refractive index at that wavelength and Snell's law. Most long wave IR (thermal) is absorbed by window glass. Exotic glass used in the lenses of your objective don't.

 

[teratos]

Do you want to move around at night(nightvision) or detect warm-blooded things(thermal)? Those are the jobs each does.

I was thinking about this very thing on the way to work. Thermal for seeing if anything is out there. NV for navigating.

 

[smdub]

Technically, only a fraction bounce off, the amount determined by the refractive index at that wavelength and Snell's law. Most long wave IR (thermal) is absorbed by window glass. Exotic glass used in the lenses of your objective don't.

Just about any bare metal or glass object has an emissivity of ~0 at IR. You can see your own reflection in glass and aluminum plate. We used FLIR extensively in the lab for testing. Very much like a mirror so I don't know how snell's law comes into it. For any aluminum heat sink in the lab that wasn't black anodized yet we'd just put a piece of scotch tape on it to be able to 'see' its temperature at that spot. You can not see a shiny metal object that is hot enough to burn you. Even hot raw aluminum can get to dangerous temps before really being able to detect.

The lenses in our high end FLIR were Germanium. Its a crystal but I don't know that I'd call it 'glass' Opaque to visible wavelengths but transparent at IR. FWIW, per mass, germanium is about the same cost as silver.

 

[wilcam47]

 

[gwchem]

Just about any bare metal or glass object has an emissivity of ~0 at IR. You can see your own reflection in glass and aluminum plate. We used FLIR extensively in the lab for testing. Very much like a mirror so I don't know how snell's law comes into it. For any aluminum heat sink in the lab that wasn't black anodized yet we'd just put a piece of scotch tape on it to be able to 'see' its temperature at that spot. You can not see a shiny metal object that is hot enough to burn you. Even hot raw aluminum can get to dangerous temps before really being able to detect.

The lenses in our high end FLIR were Germanium. Its a crystal but I don't know that I'd call it 'glass' Opaque to visible wavelengths but transparent at IR. FWIW, per mass, germanium is about the same cost as silver.

You can use Snell's law to determine the amount of incident light that gets emitted through an interface or reflected. But it's simplified as a ratio of refractive index (real part of the permittivity). For something like aluminum, refractive index is extremely large at most wavelengths, something true of most metals. Glass is lossy, the light is absorbed instead of reflected, but in the end same effect to your optic.

Technically, emissivity is not what we're talking about, where the inability to use thermal through glass is due to transmission. Emissivity is the relative amount of light given off by the material at that temperature.

 

[Alea Jacta Est]

Thermal for detection

NV for engagement

 

[44man]

So can people see when the or light is on with the naked eye at night?

Can others with any kind of night vision see your ir light like a flashlight beam?

 

[RRomig]

You’re going to get a certain amount of night blindness from looking through the optic. I use the same eye for scanning as shooting so I have one good eye to see where the hell I’m walking. I also find white hot to be the easiest on my eye but I know people that like black hot better.

 

[teratos]

You’re going to get a certain amount of night blindness from looking through the optic. I use the same eye for scanning as shooting so I have one good eye to see where the hell I’m walking. I also find white hot to be the easiest on my eye but I know people that like black hot better.

I prefer the white hot as well.

 

[steves1911]

So can people see when the or light is on with the naked eye at night?

Can others with any kind of night vision see your ir light like a flashlight beam?

Ir is invisible with the naked eye but yes anyone with a NV will clearly see another IR light. A small ir strobe in a bdu pocket is visible from a long ways off with decent NV.

 

[44man]

Ir is invisible with the naked eye but yes anyone with a NV will clearly see another IR light. A small ir strobe in a bdu pocket is visible from a long ways off with decent NV.

I have always wondered about that

Thanks

 

[erwos]

We messed around with the HS1 tonight, and it seems reasonable for the price. Good enough for scanning, anyways. I'll provide a 30mm QD mount and see how it is as a sight.

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