Posts Tagged ‘night goggles’

Where Did Night Vision Devices Come From

Tuesday, February 9th, 2010

The night vision equipment used by consumers today has its origins in the armed forces. The army also responsible for lots of other things like the world wide web, freeze dried food and the global positioning system just to name a few. But when it comes to night vision technology I’m not talking about the stuff that your children might play with, but the Real McCoy.

 

In the early days of warfare like today it was common for a operation to take place at night . The reason I think is very obvious. A unit of soldiers are able to keep the element of surprise until the last moment of attack. Now in the past this was not always possible as you can only see as much as your enemy can see so attacks were usually planned for clear moonlit nights which gave better night vision. But as you know this also hampered the element of surprise. The US Army have researched tirelessly for years researching many methods to enhance a soldiers vision at night and thanks to their advances the whole playing field of combat warfare has changed dramatically not to mention the many uses for this technology in the civilian world.

 

Night vision optics gather the available light by using electro magnetic radiation that is out of the range of the human eye. Making use of this available light allows night goggles, binoculars and scopes the ability to see in total darkness. At dusk and in low visibility conditions the night vision technology allows a soldier to see, maneuver and engage in combat.

 

Although this night vision scope technology is continually improving the two types commonly used are: image intensifiers and thermal imaging devices. Thermal devices work by looking at and understanding the differences in temperature in the direction they are pointed. The FLIR (Thermal Forward-Looking Infrared) detector option is often used on the armed forces vehicles and rescue helicopters.

 

Now image intensifiers work by magnifying available light 2-5000 times more than what the human eye can see. The intensified light makes use of phosphorous screen technology (similar to that used in a TV)enveloped in an eye piece to give the user as close to normal vision as possible. When a soldiers eyepiece is in place, the equipment will amplify available light allowing an image to be transmitted to the eyepiece giving the soldier an image of what he is looking at. The phosphorous monitor or screen is green in color. The human eye can recognize more levels of green than any other color in the visible spectrum eanabling the soldier to see better in the darkest conditions.

 

There are a high number magnifications available for different lenses as well as different conditions and ranges. Different things work for different conditions and situations and this is something the military had to deal with also. Although a soldier needs the best equipment possible other things like portability, weight and cost had to be taken into account. So by using a night vision binocular with image intensifiers only the weight was kept to a minimum and soldiers could carry out there missions in low light. This would ensure the US Army kept their cost down.

 

A couple of things you should know if you do get a set of night vision goggles is you will get a certain amount of tunnel vision because your peripheral vision is cut off within the eyepiece. By constantly moving you can counter this loss of judgment to a certain extent but judging distances can still be an effort at times. Another point to remember is that objects can seem larger or smaller than what they actually are. Usually a user’s vision can go from 20/20 to 20/25 but 20/25 is still better than no vision at all. The military have the option to work under the shroud of darkness, much like their enemies, allowing for a better chance to capture and defeat when necessary. FLIR’s really do help in locating any thermal energy whether it be human or animal in lots of different conditions and that is why the night goggles technology is used by security and rescue personal alike not to mention the outdoors man as well.

 

Tips For Selecting The Best Hunting Scopes For Your Application

Monday, February 1st, 2010

It is common for rifles and shotguns to look like something is missing when no hunting scope or other kind of sighting device is attached. They are becoming more and more popular for handguns, too. The main reason is that it makes it less difficult to hit your target, when it is further away, even though the firearms can have the iron sights built in. By looking into a magnifying scope or using a red dot laser sight, it is easier to see your target and get a more accurate shot.

All rifle scopes feature a sizing system called a number range, these numbers refer to a hunting scope’s magnification ranges and the diameter of its objective lens. The first numbers of a 3-9x 40 scope would mean it is a variable optic capable of 3 times closer than the naked eye and up to 9 times the naked eye in magnification. The important thing here is how low is the magnification, not how high. This is because as the magnification increases, the extent of light through the eyepiece is less.

The last number of the number range shows you the diameter of the objective lens, measured in mm. Generally, gun scopes use objective lenses with diameters of 40 to 45 millimeters. Some more extreme models range up to 75 millimeters, but this isn’t needed. The bigger the objective lens number, the larger it will be and the more light you will get through the scope. It is this fine balance of magnification and objective lens size than gives the best detail, this is essential for the most accurate shot.

Picking magnification size depends on how much magnification you will require. You should not forget that the lower the magnification, the greater the detail, but you also need to consider the size and distance of your targets. You want to select a 3-9x 40 hunting scope for hunting large targets like deer, but for smaller, more distant targets like pheasants or squirrels, you might need a 6-20x or an 8-25x variable rifle scope.

A scope’s objective lenses also can be variable or adjustable. External parallax adjustments can alter the diameter of variable objective hunting scopes. This can make a difference with hunting scopes with greater than 10x magnification. You won’t generally get this feature on optics with less magnifications.

Hunting scope lenses generally are water resistant and fog-proof. They are coated with one or more layers of coating to help lower loss of light and glare. Generally speaking, the more layers of this coating you have, the more defined the contrast and the better the object’s image will be. Hunting scope lenses which are fully multi-coated are always seen as the best because they usually give greater light transmission and give a sharper contrast.

Another phrase you will hear while you’re looking at hunting scope optics is Field Of View, or FOV. Field of View is refering to how many feet, left to right, you will be able see when looking through the scope. Normally your FOV at a 100 yard measurement using 3x magnification can be about 30 feet. As the magnification you use gets smaller, the Field of View goes up. At 9x magnification, the FOV is only about 14 feet.

You need to understand a rifle scopes dimensions when you are choosing the best overall scope for the kind of hunting you will be doing. As you now know, the measurements can make quite a difference in how precise your shots will be.

Tips For Selecting The Best Hunting Scopes For Your Application