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Posted: 6/4/2008 7:01:38 AM EDT
I've been reading some of the stuff posted here and see a lot of misinformation going on. So I'd like to clear up certain things that I see that get repeatedly asked.

Gen 4 - People called it a marketign ploy. Is it really? Sort of. First off, Litton came up with an autogated power supply to get into re-bid of NV contract. At one point, ITT was the sole supplier to the military. Litton was prevalent back in the day. Litton introduced Autogated power supply and proceeded to declare Gen 4. Shortly, ITT came up with the same thing and they called it Pinnacle. Army NVL (Night Vision Lab)/NVESD (Night Vision Electronic Sensor Directorate) basically came out and said no no, this is not advanced enough to call it the next generation. So they both reverted back to Gen 3 with autogated power supply....while ATN is still high calling all of their products Gen4.

Digital Night Vision - Get over it already. This is your CCD camera with "hot filter" removed. Sony has been doing it for decades with their "Night Shot" mode. If you have a sony digital camera that has that mode....when you switch, you'll hear the click sound. That's actually hot filter got flipped out of the optical path....which allows ou to see beyond 700 nanometer (nm). So do you really think something that Sony did decades ago is still "the way of the future"? I think I ran off a strong digital night vision supporter from this board already....maybe he'll be around again.

Autogated power supply - This is actually an old method of dimming light, etc. It uses Pulse Width Modulation (PWM). It's just been recently incorporate into image intensifiers not too long ago.



Link Posted: 6/4/2008 7:26:14 AM EDT
Link Posted: 6/4/2008 6:54:59 PM EDT
IMHO, I think digital vision has plenty of room for improvement, but, the stuff on the market is just not there to prove it out.

Link Posted: 6/4/2008 7:33:53 PM EDT
Bump
Link Posted: 6/5/2008 3:26:30 AM EDT
Good to see you too Victor.


More myths to debunk:

10,000 Hours MTBF in Gen 3: It is exactly what it says. This myth has more to do with the definition of MTBF (Mean Time Between Failure). Many people misunderstood this definition as 10,000 hours and your tube will die. This is absolutely false. Your tube may have life more or less than 10,000 hours. Let's examine the definition - Mean (aka average) time between failure. What this means is that they take a batch of Gen 3 tubes (hopefully enough statistical sample, at least 30) and run them until the tubes are dead. Basically, the average time that these tubes go bad is 10,000 hours. People always asked how many hours on the tube? The question is almost pointless. People think oh, it's got 1000 hours, therefore 9000 hours left. This is completely false. It's like buying a car with 50,000 miles on it - Do you know when that car is going to die? No, better question is how did you take care of it.

FLIR VS I2 - I will be very reserved about this topic as this is a free access forum (hence, anyone in the world can log on and see this).

I^2 works in visible (VIS) light arena, which works off reflection of light. It may sounds stupid, but it is an important concept to grasp. It works by amplifying the input light. The photocathode (PC) is the photon (light) to electron converter. Gen 3 has GaAs (as those in the industry pronounce this "gas", Gallium Arsenide) photocathode. After PC, the Microchannel plate (MCP) amplifies the number of input electrons. The phosphor screen is after the MCP, which its function is to display. Different phosphor deposit gives different tone of color. Beyond that is the fiber optics, which may or may not invert the image (hence they specify inverting or non-inverting tube).

FLIR (thermal) works of emission of heat and detecting the temperature difference. Its bands are Short, Mid, and Long wave Infrared - SWIR, MWIR, and LWIR respectively. The bands are limited due to atmospheric transmission and absoprtion and not because of semiconductor cannot be doped to work in the range between - what's the point of making a receiver that your atmosphere won't transmit. The heat emission is another hard concept to grasp. People think since foil reflects light, it will reflect heat. Heat conducts, emits, and radiates. So if you were to put a foil blanket over you, eventually the foil will reach the same temperature as your body heat - you will be visible to FLIR within seconds.

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