Diopter adjustment

Roughly all binoculars have a “diopter adjustment” which allows you to set the two sides of your binoculars to match the differences between your eyes. You can find it on the right side, you can see zero marked between a plus and a minus sign. Make sure its at zero before you start this adjustment.
• Place the lens cap or the palm of your right hand over the right objective lens (or the left hand over the left lens if that’s the side with the diopter adjustment) and focus on the object using the central focus. Make the focus as crisp as you can. Try to do this without closing your other eye.

• Switch your hand or lens cap to cover the other objective lens, and now make the same object as crisp as you can using the diopter adjustment.

• Switch your hand or lens cap again to double check how good the focus is-if adjustments are necessary, use the central focus.

• Then switch your hand or lens cap one last time, and fine tune the diopter adjustment.

• Now look through both lenses, and make sure the object is well-focused. Focus on something closer, and something farther away, using the central focus, to make sure the binoculars are set right. Then notice exactly where the diopter adjustment is set. This is where it should stay whenever you use your binoculars. (If you sometimes wear different glasses or contact lenses, your diopter adjustment setting may be different in those situations.) You should always use the center focus now.

Once in a while you should retest the diopter setting in case your vision has changed.

Bookmark It

Hide Sites

Travel Binoculars

Binoculars are most often used by people who travel. Binoculars are mainly helpful in journey travel, such as traveling to national parks or safaris, where the explorer might want to view wildlife. Travel binoculars are usually lighter and more solid than usual binoculars. They effortlessly fit in a carry on bag, and some are tiny enough to fit in a pouch.

Machinery of Travel Binoculars

It’s always good to know the working of binocular before you choose.

Prism

With the help of prism you see the images right-side-up when looking through the binoculars. Travel binoculars usually have roof prisms, which are present inside the optical tube of the binoculars. It reduces the space and makes it great to travel.

Lens Coating

Glass surfaces are coated that touch the outside air. The coating helps transmit the light. Its better to look for binoculars which are fully coated. Multicoated binoculars reduces glare.

Magnification and Objective Lenses

Magnification is the power of the binoculars. Magnification is usually confirmed in two numbers, such as 8 x 25. The first number means how much the binoculars magnify an object. An 8x magnification means that the object looks eight times closer than natural eyesight. The second number is the objective lens diameter. The lesser the diameter, the more compact your binoculars are for travel. However, the larger the diameter, the more light you will have entering your binoculars. The objective lens is the lens that faces the object.

Exit Pupil

The exit pupil is the lens by your eye. If you hold the binoculars at arms length, you will see a small spot of light through the eyepieces. This is the exit pupil.

Field of View

You will have a limited field of view, which is the area you can see when looking through your binoculars. This area is measured in degrees. If you are going to be watching moving objects, look for a large field of view.

Source: http://www.travelequipments.com/travel-equipments-articles/discount-binoculars.htm

Bookmark It

Hide Sites

Carson XM-832HD 8×32 XM-HD Binoculars with High Definition Optics 8x 32mm
Price: $364.49

They provide good quality binoculars for the customers. From full size binoculars, as well as Compact Binoculars, Carson Binoculars will please any kind of customers. They believe in originality, high-quality and extraordinary value.

In Carson’s XM-832HD they have introduced a new HD optical coating technology to ensure the brightest, sharpest images possible. They are shock proof, water proof and fog proof. This binocular gives extra long eye relief with twist down eyecups.

Bookmark It

Hide Sites

Nikon Sports & Marine 7×50 Binoculars
Price: $324.49

Nikon binoculars are built to handle the real world with superb optics, incredible ruggedness and the optical performance. Nikon Binoculars are well known for their quality and performance. Their main criteria are customer satisfaction. All the models features finely tuned ergonomic engineering for comfortable handling during long hours of use.

Nikon Sports & Marine 7×50 Binoculars are fog free with O-ring seal and nitrogen gas. It has Built-in compass with illuminator and scale. For a clear field of view they have designed High-eye point for wearers of eyeglasses. They are shock resistance and have a firm comfortable grip. They also provide floating strap.

Bookmark It

Hide Sites

Celestron Skymaster 15×70 Porro Prism Binoculars
Price: $87.95

Celestron’s SkyMaster Series are high performance binoculars. They are ideal for astronomical viewing for terrestrial use mainly for long distance. Each SkyMaster model has high quality BAK-4 prisms and multi-coated optics for enhanced contrast. Celestron has designed and engineered the larger SkyMaster models to meet the special demands of extended astronomical or terrestrial viewing sessions.
The 15×70 version is one of the most popular models in the series. It offers serious large aperture light gathering in an affordable and reasonably lightweight configuration.

Features

• 15x magnification porro prism binocular
• Large 70mm objective lens offers maximum image brightness in low-light and long-range conditions
• Four-element objective lens for ultra sharp focus across the field of view
• Multi-Coated optics for sharp, clear views
• Suitable for terrestrial or astronomical viewing
• Protective rubber covering for ultra-firm grip
• Large center focus know for easy focusing
• Tripod adapter included
• Long eye relief ideal for eyeglass wearers
• Carrying case included for travel and safe storage
• No Fault Warranty provides best protection and product support on the market

Bookmark It

Hide Sites

Night Owl Optics National Geographic Binoculars - 5.0x
Price: $893.49
Night Owl Optics National Geographic Binoculars - 5.0x device has top quality optics. It is the perfect product if you want value for money .The body of the binocular is coated with two piece rubber which gives extended life and a built-in high quality Infrared Illuminator. These binoculars also provide Auto-Gain control to remove negative effects of bright light. It also comes with Pelican Watertight Protective Cases. They are very user friendly. Ergonomic design for comfortable handling. It has got Soft-touch on/off and IR control buttons. Uses 2 x AA batteries. It weighs 40 ounces. The camera is easy to use and has various settings which you can use to alter the shutter and aperture speeds. It has automatic focus, which can be overridden to manual. You can also alter the settings of the pixels used, so that you use less memory.

Bookmark It

Hide Sites

Night Owl Optics NOTG2 Night Owl Tactical G2 Binocular Goggle
Price: $3337.88

Night Owl Optics NOTG2 Night Owl Tactical G2 Binocular Goggle is one of the most sophisticated commercial night vision units. It has got dual oculars for comfortable viewing and a single objective lens for easy focusing. NOTG2 can automatically adjust the image brightness to the natural light conditions. It has an infrared illuminator which allows the user to see in complete darkness. Its extended range infrared illuminator, which can be easily attached to the unit, and the 4x lens, which interchanges with the standard 1x lens and provides extended viewing distance along with greater magnification. Night Owl Tactical Goggle Bi-ocular can be used as a stand alone night-vision bi ocular (Night Owl NOTG2) or with the night vision head mount (Night Owl NOTBG2).The NOTG2 employs the state-of-the-art Generation-2+ intensifier tube with built-in micro-channel plate and provides bright- distortion free images. Night Owl Optics NOTG2 Night Owl Tactical G2 Binocular Goggle can also be flipped up and out of the line of vision. The head mount gear of Night Owl Optics Bi-Oculars is comfortable and has push button which gives flexibility for the Night vision goggle unit.

Features

•Built-in infrared illuminator allows use in complete
darkness
•Wide field of view - 50º
•Highest grade optics with as much as 21 elements in each
ocular
•Automatic light protection censor
•Accessories sold separately: Extended range infrared
•4.0x magnification lens

Bookmark It

Hide Sites

Canon Provides an excellent technical reference guide on binoculars, including image stabilization here.

Bookmark It

Hide Sites

How to Choose the Right Pair of Binoculars for You

There are several factors to consider in making a good choice of binoculars.

How important each binocular factor is to your selection will depend on how you plan to use them.

Important binocular properties;

• Magnification

Binoculars are almost always identified as number with X then a second number, such as ‘7X50′. Magnification in this example is 7X. Natural expectation for people is to want higher magnification but higher magnification comes at a price more than money. The higher the magnification the harder it is to hold what you are looking at steady. Since most uses of binoculars are hand held, having excessive magnification is not desirable.

• Brightness

The second number after magnification is the example above 7X50 is the diameter of the ‘objective’ lens in millimeters. The objective lens are the larger ones on the far side of the binoculars (see diagram courtesy of Nikon below). The size of the objective lens is important to brightness as the larger they are, the more light they are gathering for your eyes at the other end. If you think of photons as a quantity of ‘information’, the more photons the lens gathers and bring to your eyes, the more ‘information’ your brain will have to enjoy. However the trade off for larger objective lens are the binoculars will be more heavy and bulky.

• Exit Pupil

The light that does get to your eyes has an effective area called the ‘exit pupil’. This can simply be calculated using the 7X50 specification if you divide the 50 (objective lens diameter in mm) by the magnification (7X), which in this case is slightly more than 7mm. The pupils of your eyes are less than 4mm wide in bright daylight so in this case there is ample efficiency. However in low light situations the pupil expands to 7mm when you are younger (not as much as you get older). So if you are older than 40 and using 7X50 binoculars in a low light situation you will likely see a darker view than with a pair of 7X35 binoculars with a 5mm exit pupil.

• Weight & Bulk of Binoculars

Weight is not an optical property but can be a crucial factor in how useful the binoculars you choose are. As mentioned above having high magnification won’t mean much if they are too heavy to lug and hold steadily up to your eyes. More expensive lighter lens materials can offset this if you can afford it. Also more expensive “roof prism” binoculars are more compact are an option again if you can afford it.

• Field of View

Field of view for binoculars is most often expressed as ‘X’ number of feet at 1000 yards. The higher the magnification the smaller the field of view will be. You can improve field of view for a given magnification with more expensive “wide angle” binoculars. For birdwatching or Astronomy 300 to 400 feet at 1000 yards will be acceptable. It is a challenge for 10X magnification binoculars to be above 300 feet at 1000 yards.

• Optics (lens, prisms, and coatings) Quality

• Ideally you want to avoid poor quality optics , start with good quality, and then decide later if you want to move to superb quality optics. There is no point to buying bargain basement binoculars or poorly maintained used binoculars as your experience will be disappointing. Preferably all optics are coated and better still multi-coated. Coated optics improve light transmission. Look for the phrase “multi-layer coated optics” and be wary of the phrase “fully coated optics” as this might mean that only external air to glass surfaces are fully coated but other internal lens and prisms may not be. Light transmission loss occurs at all surfaces without anti-reflective glass coatings. I will explain how to visually check for coatings in a later post.

• Resolution - High quality lens provide good color fidelity, are free of optical aberrations, and provide excellent detail.

• Stabilization

Expensive electronic ‘gee-whiz’ adjusting system that noticeably improves the view, especially in hand held use targeting moving objects. An interesting experiment is to take a ‘value priced’ pair of binoculars and look at the moon holding them as steady as you can. Then mount the same binoculars on a steady camera tripod and look at the moon again. You will be shocked at the extra detail that you can see due to stability.

• Rugged, Waterproof, Fogproof,

Having rubber overmold on the binocular body does not always mean they are rugged. Search for drop specifications if rugged is important for how the binoculars will be used. Waterproof is important for hunting and marine use as well as fogproof. Waterproof is specified usually in a JIS or IEC 529 rating (click on the link to understand more about waterproof ratings). An IEC rating of IP64 will suffice or look for IP67 if you want to take your binoculars swimming. Fogproof binoculars have the air inside replaced with a gas such as Argon or Nitrogen.

• Porro prism vs Roof prism

Binoculars you are most likely to be familiar with are porro prism with a prism system moving the two light paths from the objective lens closer together on the way to the two eyepieces you look into. “Roof” prism binoculars are “straight through” looking. This lens system is more expensive but has the advantage of allowing for smaller compact configuration and storage. They also look better as a fashion statement if that is important.

Bookmark It