All pictures were taken at different conditions. E.g. 5351577 has a full moon and 6351138 has a paritial moon. Purpose of picture is to show overall quality of the specific tube (black spots mainly).
The GT-14 is a high-performance night vision monocular with advanced ergonomics and intelligent power control developed as an alternative to the standard PVS-14. It can withstand salt water, rain, high humidity and extremes of temperature, and you will get high levels of performance.
GT-14 can be used hand-held, head or helmet mounted and weapon mounted. All GT-14 units are equipped with automatic brightness control (ABC) and in-ocular IR and Low Battery indicators. This system automatically adjusts the brightness of the image tube. As a result the users will get the highest quality image resolution under varying light conditions.
Photonis Commercial image intensifier tube is a huge improvement compared to standard Gen2+ tubes with higher sensitivity, resolution and signal to noise ratio.
* This unit is not Autogated.
IIT: Photonis Commercial Gen2+ White Phosphor
|Luminance sensitivity 2850 K.||270||570||/|
|Radiant sensitivity 830 nm||17||55||/|
|Luminance gain (at 20 μlx)||3000||5000||6000|
|Signal to noise ratio||12||21||/|
|Equiv. Background illumin.||/||0.15||0.40|
* Even though the minimum specs are really low, every unit we have ever encountered has specs pretty close to average. We have never seen a Photonis Commercial with FOM less than 1000.
|Image Intensifier Tube (IIT)||Photonis Commercial Gen2+ White Phosphor|
|Diopter compensation||-6 to +2 dpt|
|Battery Life||50 h|
|True field of view||40°|
|Close focus limit||0,25m|
|Power Supply||CR123 or AA|
|Dimensions||120 x 50 x 60 mm|
The ability of an image intensifier or night vision system to distinguish between objects close together. Image intensifier resolution is measured in line pairs per millimeter (lp/mm) while system resolution is measured in cycles per miliradian. For any particular night vision system, the image intensifier resolution will remain constant while the system resolution can be affected by altering the objective or eyepiece optics by adding magnification or relay lenses. Often the resolution in the same night vision device is very different when measured at the centre of the image and at the periphery of the image. This is especially important for devices selected for photograph or video where the entire image resolution is important. Measured in line pairs per millimeter (lp/mm).
Lp/mm (Line Pairs per Millimeter)
Units used to measure image intensifier resolution. Typically, the higher the line pair, the better the image resolution. Generation 3 tubes generally have a range of 64 72 lp/mm, although line pair measurement does not indicate the generation of the tube. Some Generation 2+ tubes measure 28-38 lp/mm, (Gen 2+ at 54-59 lp/mm typically), while a Generation 1+ tube may have measure at 40 lp/mm.
Photocathode sensitivity is a measure of how well the image intensifier tube converts light into an electronic signal so it can be amplified. The measuring units of photocathode sensitivity are micro- amps/lumen (?A/lm) or microamperes per lumen. This criterion specifies the number of electrons released by the Photocathode (PC). PC response is always measured in isolation with no amplification stage or ion barrier (film). While for most latest 3rd generation image intensifiers the photo response is in the 1800 ?A/lm, but for the latest tubes you can expect min. 2200 ?A/lm.
Signal-to-Noise Ratio (SNR)
A measure of the light signal reaching the eye divided by the perceived noise as seen by the eye. A tubes SNR determines the low light resolution of the image tube; therefore, the higher the SNR, the better the ability of the tube to resolve objects with good contrast under low-light conditions. Because SNR is directly related to the photocathodes sensitivity and also accounts for phosphor efficiency and MCP operating voltage, it is the best single indicator of an image intensifiers performance.
Figure of Merit (FOM)
Image Intensification tube specification designation, calculated on line pair per mm x signal to noise. (FOM=lp/mm * SNR).
This is nothing else then PWM but for image intensifier tubes. Offering the tube better protection and preventing resolution loss in high light conditions.
Black & White Image (White Phosphor, WP)
By using a different kind of phosphor (P45) the image looks like a black & white picture in high definition. For some people these seem to work better than for others. Personal preference.