What is a Real Night Binocular?

Binoculars are Popular

Binoculars are very popular nowadays. This is not surprising as they are no longer the preserve of the military and police forces. They are now commonly used in a lot of outdoor recreational activities. For bird watching they are essential, but just about any pursuit can be enhanced by the use of binoculars. If your pleasure is fishing, boating, camping, hiking or hunting, you find that a pair of binoculars is a useful addition to your equipment.

Since these activities can be enjoyed at any time of day or night, you might think that night vision binoculars would be a good idea. Adverts for these are becoming quite common now and they can be obtained not just from army surplus stores, but from good outdoor equipment retailers and from many online sources. But don’t just jump in and buy them. Not without some guidance.

Uses of Night Vision

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Types of Binoculars

There are different types of binoculars for different purposes and without some guidance, you could be disappointed with your new acquisition or end up paying more than you need to, for functionality that is beyond what you really need.

So, what are the differences?

A true night binocular is intended for use when there is no or virtually no light. But there are also binoculars that are able to operate in very low light conditions. If your activity takes place at dawn or dusk, these might be suitable for your needs and are likely to be less expensive than night vision binoculars. Some technical information might be useful in this regard.

Low Light Binoculars

One factor that influences low light performance is the ‘exit pupil’ of the instrument. If you hold a pair of binoculars a couple of feet away from you, you will see small circles of light in each eye piece. This is the exit pupil. It can be calculated from the information provided on the binoculars. On the body, there is usually a pair of figures separated by an x, for example, 12x50. The first figure is the magnification factor. In this case, an object viewed through the glasses would appear to be 12 times larger than if seen with the naked eye at the same range.

The 50 refers to the diameter of the lenses in millimetres. Obviously, the size of the lenses sets the limit on the total amount of light that can enter. If you divide the diameter by the magnification, 50 divided by 12, you get just over 4mm. This is the size of the exit pupil. A larger exit pupil will give better performance in poor light. A larger exit pupil also makes it easier to keep an object centered in the glasses. But it is not the case that bigger is better. There are problems associated with an exit pupil larger than the diameter that your own pupil can expand to. This tends to reduce with age. You can see why it pays not to make a rash purchase.

Low Light and Night Vision

True Night Vision

This type of binocular might be OK if you operating early or late in the day. But if you will be hunting or hiking in the night, you will need a true night binocular. If there is very little or no light at all, you will need an instrument with its own internal light source. An infra red light can produce remarkable results. If you haven’t experienced night vision, you will be amazed at what can be seen. What you have to take into account here is the range of the light source. If you are hunting and you can only see 10 yards, your quarry will be long gone. Consider what sort of range you will need.

Types of Optical Device

We should look at the different types of optical devices and their uses. A monocular looks similar to a telescope. It is sometimes called a spotting scope which gives an indication of what it is used for. That is, surveying the terrain for one of your companions and also in astronomy, for lining up your main telescope.

A bi-ocular has two eye pieces both viewing through a single front lens. This will feel more normal for most people but is a compromise. The two front lenses of a true night vision binocular allow both eyes to be equally adjusted to the night vision viewfinder. If you will be using them for long periods rather taking an occasional sighting, the real night vision binoculars will be the more comfortable option.

Wildlife at Night

Conclusion

As you can see, there are several factors to be considered before making your choice. Do you really need night vision or would a good pair of low light binoculars suffice. For night time, could you save money by going for a bi-ocular if you will use it infrequently? Does the build quality need to be OK, or truly rugged and waterproof? It depends on your application. And there is always the question of budget. How much are you willing to spend on your new toy?

True night vision binoculars can cost a few hundred dollars and may be beyond what you really need. It pays to do some research and consider what your application requires, before you go out to shop.