Bushnell Night Vision FAQs

Here is a great write-up provided to us by Bushnell.  We present it here in order to help you with your Night Vision selection.  As with any other product offered in our online Optics Planet, email us info@opticsplanet.com with any questions that you might have.

Answers To Your Frequently Asked Questions About Night Vision.

Q. What is Night Vision used for?

A. Recreational uses consist of camping, hiking, fishing, boating, and nature viewing. Other uses include surveillance, search and rescue, and property management.

Q. What is the difference between night vision generations?

A. The key difference between the night vision generations is the intensifier technology. Gen. I devices use an intensifier tube that amplifies ambient light by accelerating electrons and striking a phosphor surface just like a Television. Generation II devices add a micro-channel plate that multiplies the number of electrons before they impinge on the phosphor screen, thus increasing gain; Generation III devices further add a Gallium Arsenide photocathode which creates significantly more photoelectrons than Gen. II devices. Generation II and III devices offer greater light amplification but a price beyond the reach of most buyers. Generation I devices are high quality and provide light amplification adequate for most recreational activities and for many professional uses.

Bushnell has introduced an Advanced Night Vision device that produces images comparable to Generation 2 devices. The Advanced Night Vision device does not contain a Micro Channel plate, but uses fiber optic bundles to eliminate distortion thus providing excellent resolution and a flat field of view. The result is superior image quality comparable to Generation 2 devices at half the cost.

Q. How does Night Vision work?

A. Bushnell Night Vision products collect and amplify existing light through the objective lens which is then focused on the image intensifier. Inside the intensifier, a photocathode is "excited" by the light and converts the photon energy in to electrons. These electrons accelerate across an electrostatic field inside the intensifier and strike a phosphor screen (like a green monochrome TV screen) which emits an image that you can see. It is the acceleration of electrons, which provides gain and enhances the image.

Q. Aren't all Night Vision products the same?

A. No. Only Bushnell Night Vision comes from a proven Leader and Innovator in the Sports Optics Industry.

Q. What is the effective range of night vision?

A. It varies anywhere from 1-1800 feet. The maximum viewing distance depends on the conditions of use and upon model chosen. Overcast conditions, fog, rain; etc. may reduce the effective distance of a night vision. An Infrared Illuminator will increase viewing range, especially in enclosed areas like a warehouse, cave, or thick brush.

Q. Why isn't there more magnification in a night vision device?

A. The more you magnify the more light you lose.

Q. Why do you focus both the front (Objective lens) and Eye-piece (Ocular)?

A. The short answer is that you don't see through the night vision device, rather you see the phosphor screen on the back of the tube. The objective lens focuses the image on to the front of the intensifier tube. That image is then converted in to electron energy. It paints that picture on the back of the tube. You need to have a sharp image to start with. Then your eye needs to be focused onto the back of the tube where the image resides. Every eye is different and therefore the ocular focus is very important. Focus the ocular first and then move to the objective lens. You may have to adjust each lens several times before getting a sharp image.

Q. How do I use a Bushnell Night Vision device in extremely low light, or no-light conditions?

A. All night vision devices need some available light to work. It is possible to see a bright image in low light or no light conditions with the use of an Infrared Illuminator. An Infrared Illuminator is standard on all Bushnell Night vision devices.

Q. Since a night vision device is sensitive to Infrared (IR) light, can it detect heat?

A. Night vision devices operate as a light amplifier for light in the "near visible" light range. Generally, this is in the 750-850 nanometer range. It can not detect heat, which is at a much lower end of the light spectrum and requires thermal imaging technology.

Q. What type of light source can be harmful to a night vision device?

A. Night Vision devices are designed for use in the dark. It may be harmful and can damage the device if you use it during the daytime or in other very bright situations. Keep in mind that strong direct light, such as projectors, car headlamps, strong flashlights, and so on, may be harmful to your night vision unit if you direct your device at the source of these intense lights. With this said, Bushnell Night Vision devices have electronic protection against such damage. Most of these are simple turn off overload circuits, but some have more sophisticated and separate light sensing mechanisms.

Q. What characteristics might I expect from my Night Vision device?

A. All Bushnell Night Vision Monocular scopes are activated in a way that can not be left on when not in use. The power button is designed to give power only while being depressed.

The binocular devices do have on/off switches that require the user to remember to turn off the unit. Some level of "buzzing" sound is quite normal and is intended to be useful in remembering to turn off these units when done using them.

The image of a night vision device will not be as sharp as that of a daylight binocular. This is due largely to the image being generated on a phosphor screen.

Black spots may be visible in the image. This comes as a natural process of manufacturing the intensifier tubes.

Q. What's inside a night vision scope?

A. A night vision scope is made up of a set of optics (glass), a simple power supply (batteries, wire, transformer, regulators and capacitors) and an image intensifier (a glass vacuum tube with a light sensitive coating at one end and a phosphor screen at the other).

Q. Are Bushnell Night Vision devices safe?

A. Yes. All of Bushnell's Night Vision products include shield-encased image intensifiers to block x-rays. All of Bushnell's infrared illuminators utilize harmless filtered incandescent bulbs or light emitting diodes (LED's) instead of lasers.

Q. How should I care for my Night Vision device?

A. The number one damage factor is using the device in bright light. While all Bushnell Night Vision devices have a cut-off circuit when over exposed, exposure will shorten the life span of a night vision device.

• Exposure to rain, fog, or even extremely high humidity may damage night vision devices. Built for use at night, they can withstand short exposure to dampness or high humidity conditions.
• Night Vision devices have delicate vacuum intensifier tubes that are sensitive to impact and should be handled carefully.
• Clean lenses the same way you would your camera. The lenses are optically coated and may be scratch if abrasive material is used or if dirt is rubbed into the glass. Usually there is no need to remove the lenses and clean inside.
• Storage for long periods is best in a cool dry place with the batteries removed.

Q. What is the warranty for Night Vision devices?

A. Bushnell Night Vision products are unquestionably warranted to be free of defects in material and workmanship for two years after the date of purchase. In the event of a defect under this warranty, we will at our option, repair or replace the product.
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