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PREGUNTAS FRECUENTES

  • WHAT IS FOM (FIGURE OF MERIT) ?
    FOM is a number calculated by multiplying the Signal-to-noise ratio by the resolution of a night vision image intensifier. FOM number allows quickly estimating the general performance level of the specific night vision image intensifier and, consequently, the night vision device built around it.
  • WHAT IS AN IR ILLUMINATOR ?
    This is an IR Light Emitting Diode (LED). When turned on, the IR Source provides additional illumination to enhance existing light conditions and aid the performance of the night vision device. Ideal for map reading and is for short-range use.
  • WHAT IS YOUR PROCESSING TIME?
    After receiving your order, it will take approximately 1-2 business days for processing. At that time your credit card will be charged.
  • WHAT IS LP/MM (LINE PAIRS PER MILLIMETER)
    A measurement of image intensifier resolution. The more line pairs per millimeter, the better the resolution.
  • HOW DOES NIGHT VISION WORK?
    In Generation II and III systems, the objective lens collects minute particles of light (called photons) that you cannot see with your naked eye and focuses then on the image intensifier. Inside the image intensifier tube, a photocathode absorbs this light energy and converts it into electrons. These electrons are then drawn through the micro channel plate that multiplies them thousands of times. When this highly intensified electron image strikes the phosphor screen, it causes the screen to emit light that you see. Since the phosphor screen emits this light in exactly the same pattern and degrees of intensity as the light that is collected by the objective lens, the bright night time image you see in the eyepiece corresponds precisely to the outside scene you are viewing. Performance is the most important factor in night vision capabilities. Will a particular device allow you to see objects in near complete darkness? Night vision equipment offered by our partners will provide high quality images under extremely low light conditions such as cloudy, no moon nights. There are several terms used to compare the qualities of one tube to another. These specifications, such as Resolution, Signal-to-noise, and Photocathode Response will determine how well a system will perform in these adverse conditions.
  • WHAT IS A BLACK SPOT/BLEMISH ?
    These are cosmetic blemishes in the image intensifier or can be dirt or debris between the lenses. Black spots that are in the image intensifier are common, and do not affect the operation or reliability of a night vision device.
  • WHAT IS YOUR INTERNATIONAL SHIPPING POLICY?
    We do not ship internationally. Export of the commodities described herein is strictly prohibited without a valid export license issued by the U.S. Department of State Office of Defense Trade Controls prescribed in the International Traffic in Arms Regulation (ITAR),Title 22, Code of Federal Regulations, Parts 120-130. All orders must be accompanied with our End User Statement
  • CAN I EXPORT NIGHT VISION EQUIPMENT?
    You cannot take Night Vision Equipment out of the United States. It is a Federal Offense to do so without valid U.S. State Department approval. Night Vision Equipment is both tightly controlled by the U.S. Government and heavily enforced, and falls under the International Traffic in Arms Regulation (ITAR), which states, “Export of the commodities described herein is strictly prohibited without an export license granted by the U.S. Department of State Office of Defense Trade Controls prescribed in the International Traffic in Arms Regulation (ITAR), Title 22 Code of Federal Regulation, Parts 120-130. Night Vision Devices, Inc. will not complete any transaction that requires the illegal export of products and will not assist directly or indirectly with any illegal export or re-export of any products. Full ITAR language can be found here: https://www.pmddtc.state.gov/regulations_laws/itar_official.html It is a violation of ITAR to allow any non-U.S. person to use or look through U.S. Gen III Night Vision Equipment, or to have access to any operator’s manual or documentation pertaining to U.S. Gen III Night Vision Equipment.
  • WHAT IS FIELD OF VIEW?
    The width or angle of the outside scene that can be viewed through the intensifier tubes measured horizontally and vertically.
  • WHAT IS GAIN?
    Also called brightness gain or luminance gain, this is the number of times a night vision device amplifies light input. It is usually measured as tube gain and system gain and is usually in values of tens of thousands. U.S. military GEN II and GEN Ill image tubes operate at gains of between 7,000 and 65,000.
  • EYE RELIEF
    The distance your eyes must be from the last element of an eyepiece in order to achieve the optimal image area.
  • EMISSION POINT
    A steady pinpoint of bright light in the image area that does not disappear or move even when all light is blocked from the objective lens. If an emission point disappears or is only faintly visible when viewed under brighter nighttime conditions, it is not indicative of a problem.
  • BSP (BRIGHT SOURCE PROTECTION)
    An electronic function that reduces the voltage to the photocathode when the night vision device is exposed to bright light sources such as room lights or car lights. BSP protects the image tube from damage and enhances its life; however, it also lowers resolution when functioning.
  • ABC (AUTOMATIC BRIGHTNESS CONTROL / AUTO GATED)
    An electronic feature that automatically reduces voltage to the microchannel plate to keep the image intensifier’s brightness within optimal limits and protects the tube. The effect of this can be seen when rapidly changing from low light to high light conditions; the image becomes brighter and then after a momentary delay, suddenly dims to a constant level.
  • EBI (EQUIVALENT BACKGROUND ILLUMINATION)
    The amount of light you see in an image tube that is turned on, but has no light at all on the photocathode. The EBI level determines the lowest light level at which you can detect something. Below this light level, objects will be masked by the EBI.
  • DIOPTER
    The unit of measure used to define eye correction to the refractive power of a lens. Usually adjustments to an optical eyepiece accommodate for differences in individual eyesight. Most night vision systems provide a +2 to -6 diopter range.
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