Infrared Lasers: Do They All Burn?

[bennett326]

Exactly, however as far as power goes (mW) I am definately going to be using something a bit more powerful vs the one the guy used in that article & "flooding" the IR Illuminator out more than 10 ft across.

My Girl needed to stop at Best Buy to pick up some Ink so I decided to sneak over to the Cam's & was amazed how well some could Zoom. An employee came up to me & asked what I was doing & to my suprise he kind of understood. However, for some reason he didn't understand I was to be using this device strictly at Night for Night Vision, as he kept telling me I needed to remove the IR filter. Hm, hope he figured out that at night, there would be no visible light so the IR wouldn't be an issue in my application. Anyways,

Digital VS Optical: Is this a "one or the other" thing or do Camera's come with both options. Problem with Digital Zooms is that it really isn't a true "zoom," it just enlarges the pixels & @ longer distances, it can definately sh*t on the image quality. In my application, Long Distance Zooming will be key, so finding a Camera W/ a kick-butt Optical Zoom is the way to go, eh?

many cameras now come with a ir filter im not exactly sure why. as i dont know allot about cameras. so they wont be able to detect the ir without the filter removed. thats the report he was trying to get across i think.

 

[BrittanyGulden]

1064nm comes from pumping Nd:YAG with 808nm. If you removed the KTP/LBO crystal from a 532nm DPSS laser (and then fixed the optics to work without it) you would have a 1064nm laser. The longer (>1000nm) wavelengths are used in the communication industry for fiber optics mostly. Finding a laser over 1064nm (aside from a CO2 laser) that has enough power for your application would be hard to do and very expensive.

Right, 940nm is inexpensive and "just over the threshold" into invisible. Longer wavelengths of IR require more complex equipment to detect as well. For example, FIR (thermal vision) requires that the sensor element be thermo-electrically cooled lower than background temperature in order to function. Basically, the chip has to be kept in a micro-refrigerator inside the camer in order to function.

Everything (all matter) above Absolute Zero temperature gives off FIR to some degree. In order to sense FIR you have to reduce the FIR that you and your device give off.

Longer wavelengths also propagate differently in air, as there are certain frequencies which air and water vapor absorb strongly. (This is how microwave ovens work, microwaves are just slightly longer in wavelength than FIR.)

On the Thermal Vision, so you are saying I really Can't achieve this "as it's higher up the scale on the EMS?"

In order to "achieve" thermal vision on a Camera, just replace the IR filter W/ a piece of developed film correct. However, since I am only using a Diode in the 900's, would my "Thermal Camera" be able to pick the laser up?

I am not sure what Range "Thermal" falls in but I know its much farther up the scale vs Near Infrared.

Thermal vision is definately the way to go vs IR. Really defies "outlines" of objects making them easier to see, which would be a BIG PLUS in my application since I will be using it out in the "bush"

 

[BrittanyGulden]

many cameras now come with a ir filter im not exactly sure why. as i dont know allot about cameras. so they wont be able to detect the ir without the filter removed. thats the report he was trying to get across i think.

But I am using this device ONLY at night so there wouldn't be any point in removing the IR filter.

I mean, IR filters just block out Visible Light. So at night, why would "visible light" be an issue as there isn't any.

SO removing the IR filter in my application is pointless.


On the other hand, the guy at Best Buy removed his IR filter so when he took pictures in the DAYLIGHT, they would show up as "Night vision"

 

[bennett326]

But I am using this device ONLY at night so there wouldn't be any point in removing the IR filter.

I mean, IR filters just block out Visible Light. So at night, why would "visible light" be an issue as there isn't any.

SO removing the IR filter in my application is pointless.


On the other hand, the guy at Best Buy removed his IR filter so when he took pictures in the DAYLIGHT, they would show up as "Night vision"

no 900nm is ir so is 880 etc that is ir (invisible)

 

[Sigurthr]

There are two types of IR filters; passfilters and stopfilters. (In electronics filters are either passband or stopband (bandgap)).

What the sales associate and Bennet were saying is that new camers come with IR Stopfilters these days.

IR Stopfilters prevent IR from getting to the sensor/film. IR passfilters stop visible light from getting to the sensor/film.

I still think thermal imaging is beyond the realm of your average amateur hobbyist. You would need to be well versed in all the optics, optoelectronics, digital electronics, and thermoelectric cooling techniques/methods involved to get even a rudimentary test going. FLIR thermal cameras are many thousands of dollars for a reason.

 

[bennett326]

There are two types of IR filters; passfilters and stopfilters. (In electronics filters are either passband or stopband (bandgap)).

What the sales associate and Bennet were saying is that new camers come with IR Stopfilters these days.

IR Stopfilters prevent IR from getting to the sensor/film. IR passfilters stop visible light from getting to the sensor/film.

I still think thermal imaging is beyond the realm of your average amateur hobbyist. You would need to be well versed in all the optics, optoelectronics, digital electronics, and thermoelectric cooling techniques/methods involved to get even a rudimentary test going. FLIR thermal camera are many thousands of dollars for a reason.

thanks for providing a better explanation

 

[BrittanyGulden]

There are two types of IR filters; passfilters and stopfilters. (In electronics filters are either passband or stopband (bandgap)).

What the sales associate and Bennet were saying is that new camers come with IR Stopfilters these days.

IR Stopfilters prevent IR from getting to the sensor/film. IR passfilters stop visible light from getting to the sensor/film.

I still think thermal imaging is beyond the realm of your average amateur hobbyist. You would need to be well versed in all the optics, optoelectronics, digital electronics, and thermoelectric cooling techniques/methods involved to get even a rudimentary test going. FLIR thermal camera are many thousands of dollars for a reason.

So what you are saying is I need to remove the IR Stoplifter.

OR

Buy an "older" Camera W/ an IR Passfilter. I wouldn't need to remove the Passfilter because at night, there is no visible light. (probaly not going to go W/ an older camera)


I'm young yet, I will figure FLIR out someday. IR is a good start.

Thanks for the replies!

 

[Ablaze]

If you buy a "consumer grade" camera as opposed to a "professional grade" camera it will probably not have an IR filter.

However, you can easily test the display models in the store to see if they can see 940nm, just take any remote with you. If you press a button on the remote you will see the light on the front of the remote flash (on the screen of the camera, the light is invisible to the naked eye). That's how most remotes work, by flashing patterns at 940nm.

 

[BrittanyGulden]

If you buy a "consumer grade" camera as opposed to a "professional grade" camera it will probably not have an IR filter.

However, you can easily test the display models in the store to see if they can see 940nm, just take any remote with you. If you press a button on the remote you will see the light on the front of the remote flash (on the screen of the camera, the light is invisible to the naked eye). That's how most remotes work, by flashing patterns at 940nm.

Understood,

It all depends what I can find on craigslist

Yes, thankyou for noting the wavelength on remotes. I have done this before & actually that is how this whole idea was started.

LOL, I think you would have gotten a kick out of some of the devices I made including my IR Illuminator W/ 100 + L.E.D.'s & their unique reflectors which was nearly the size of myself. I spent forever on improving this device and than I was ...introduced to lasers & a big light bulb lit up in my head

 

[Cyparagon]

If you buy a "consumer grade" camera as opposed to a "professional grade" camera it will probably not have an IR filter.

That's just not true. IR filters are damn cheap and they drastically improve the image quality. There's no reason not to include them. True, some IR filters are better than others, but the vast majority of consumer grade cameras do have filters.

400mW 808nm on a typical consumer-grade ~$50 camera:

400mW 808nm on a camera known to have no filter:

I'm told even <$10 DX cameras have filters.

 

[spyrorocks]

This $6.20 camera I know has an IR filter: Compact USB PC Webcam (300K Pixel) - Free Shipping - DealExtreme

If a cheap unknown chinese brand camera can have an IR filter, I don't see why consumer grade cameras wouldn't. I think you just made that up.

 

[bennett326]

thanks for presenting us with correct info cyparagon and spyrorocks

we dont want to confuse people :gj:

it good practice to just not say anything if you dont know the answer

 

[Chadness]

I'm so sorry to have to be 'that guy'
but duuuuude they are called crosshairs! not cross airs, lol.

 

[BrittanyGulden]

I'm so sorry to have to be 'that guy'
but duuuuude they are called crosshairs! not cross airs, lol.

..haha I am over it.

Darn I am pretty bummed on not being able to head with FIR & take advantage of Thermal. Sounds like a great way to achieve people's Passwords on ATM's n such, kiddin' :yh:

 

[Ablaze]

If a cheap unknown chinese brand camera can have an IR filter, I don't see why consumer grade cameras wouldn't. I think you just made that up.

It's simple, some cameras use an IR light to focus before taking the picture. Your cheap Chinese camera doesn't. I think you're just jumping to conclusions.

Anyhow, why are you still trying to troll this thread bennitt? Can you really think of nothing except trying to make me look bad? I would think you would have something better to do with your time.

 

[sopark4000]

I'm so sorry to have to be 'that guy'
but duuuuude they are called crosshairs! not cross airs, lol.

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