It has fully coated optics for vivid imagery meaning there is a single layer coating on all air-to-glass surfaces. The prisms are standard boroscillicate (BK-7) prisms compared to higher quality barium crown (BaK-4) glass. As the name suggests, the binocular has a magnification of 8 and a objective lens size of 21. The Bushnell Powerview 13-2514 8×21 binocular has a roof prism system that gives it its compact size compared to porro prism system models that are more bulky. The binoculars use a center focus system. The exit pupil located at the eye piece is 2.6mm.

Cons with the Bushnell Powerview 13-2514 8×21 Binocular is that the binocular isn’t water or fog proof so the person handling it may need to use caution around water or when it is raining. The BK7 prisms can also be a con because a distortion may be noticed on the edges of your view with lower level lighting. The binocular is not able to attach to a tripod.

The Bushnell Powerview 13-2514 8×21 Binocular is great little affordable binocular for many instances. It can be used during stadium sports events, hunting, birdwatching, observing nature, while on vacation, or for general use.

Compact binoculars are usually cheaper than full-sized models so those on a budget can get better optics in a compact model. For the younger user compact binoculars fit in their hands better.

Compact binoculars fall into four groups. The first group is inexpensive binoculars made with a folding roof prism is the least expensive binoculars widely available. The second group is the inexpensive binoculars made with a porro prism. When these compacts have great optics they can actually be decent binoculars for those who want a pair to carry all the time. The third group is the more expensive porro prism compacts are highly useful for those already experienced with a full sized binocular.

They offer great resolution, brightness, and ease of view. The last group is the expensive folding roof prism compacts offers outstanding waterproofing and good optical performance in a binocular that can be easily carried in the user’s pocket.
Compact binoculars are great for younger users or to have a pair of binoculars that will go anywhere.

Magnification refers to how much closer an object will appear. When looking at binoculars you will see two numbers with an X in the middle. The first number is the amount of magnification. Look for a number between 8 and 12. Less than 8 is just not very powerful. More than 12 is hard to handle without a tripod and most of us are not willing to lug one along.

When buying binoculars to get closer to the action the second factor to consider is the field of view. This is how much can be seen through the binoculars without moving the binoculars. The depth of field is usually expressed as a width at 1000 meters. Sometimes it is expressed as an angle. The larger the field of view is the better the binoculars.

As with almost all products, the right magnification and the right field of view costs more money. This is especially true with the field of view. Consider what will work in your case compared to the costs of the instrument.

When buying binoculars to get close to the action consider the magnification, the field of view and the price of the binoculars. It is a very individual choice.

Binoculars used for sporting events should have a magnification between 8 and 12X. Binoculars with magnification smaller than 8 and things are not big enough to really see and larger than 12 image stabilization starts to be a problem. Remember that the more magnification present the smaller the field of view.

Binoculars used for sporting events need a wide field of view and is more important than larger magnification numbers. Field of view is the amount of the playing field that you can see at one time.

Another choice in choosing binoculars for sporting events is the style of binoculars. There are two styles. They are roof prism and porro prism. Roof prism binoculars have fewer moving parts thus less can go wrong. They are easier to keep clean and can be made waterproof. Porro Prism binoculars have a wider field of focus. They are, however, more bulky and thus harder to carry to a sporting event.

The last choice in choosing binoculars for sporting events is the size of the binoculars. The user may choose compact binoculars which are easier to pack. Others will choose full size binoculars because they have a larger field of view, and can take in more light making it easier to see.

There are four main considerations in binoculars in sporting events. The choice is really a personal one.

Roof prism binoculars were created as early as the 1870s and much work on it was done by Achille Victor Emile Daubresse. Roof prism binoculars have less internal parts than a porro prism binocular. Roof prism binoculars also are easier to keep clean and easier to keep dry. Roof prism binoculars have a front lens that is in direct line with the rear lens.

The front lens is the objective lens while the rear lens is the ocular lens. Being in direct line allows this binocular to be more compact. The depth of field can present problems when using roof prism binoculars. Most roof prism binoculars use prisms that were designed by Ernst Karl Abbe and Albert Koenig or the Schmidt-Pechan prism. With these prisms the image is first erected then folded along the optical path.

Porro prism binoculars were invented by Ignazio Porro in 1854 and further improved by Carl Zeiss. Unlike the roof prism binoculars the objective lens is not lined up with the ocular lens. Therefore these binoculars require occasional recalculation by a professional. When used the objects usually appear brighter than when using a roof prism binocular. They are usually cheaper to produce and cheaper to buy than the roof prism binocular. They are harder to keep clean and water can damage these binoculars severely.

There are many similarities and differences in these two types of binoculars.

This binocular features a 70 mm objective lens which allows for the most light to be seen on the subject. The Celestron SkyMaster 15×70 Binocular features the great BAK-4 prism that is known for its great optical quality allowing the viewer to see a truer round than other common glass. The binocular also features a 4 element objective lens which allows for super sharp focusing clear across the field of view. The lenses are all multi-coated which allows for the most light to enter the binoculars and also allows for sharp crystal clear views.

The Celestron SkyMaster 15×70 Binocular features diopter adjustment allowing the user to focus each eyepiece independently. After the diopter has been set the binoculars further can be focused with the very large center-focus knob. Users will also appreciate that the binocular is water-resistant and comes with a lifetime no-fault warranty.

The Celestron SkyMaster 15×70 Binocular will provide years of enjoyment with its performance. Rather the viewer is looking at craters on the moon or a comet this binocular is an outstanding source when there is simply not time to set up the telescope.

Many companies make binoculars, but the best are made by a few companies that produce quality products. Choose binoculars from companies that have been around for a while. Those companies are prepared to stand behind their products. They also usually use a higher quality glass.

The second factor is to buy from a knowledgeable person. Rather buying online or in a store look for a sales clerk that understands the qualities of good binoculars and can help educate you on what makes good binoculars. It is a very specialized field and knowledge can be hard to find. It is also usually better to buy from a company that service their own products.

It is also important to buy based on the purpose of the binoculars.

The last thing you will want to consider is how the binoculars fit in your hands. Try to find a source where you can actually hold the binoculars before you buy them or can easily return them if need be. When you hold the binoculars you need to be able to hold the binoculars easily. The focus know should be easily accessible.

So when buying binoculars consider:
• Buy from a great company
• Buy from a good sales person
• Buy based on the purpose
• Buy based on individual feel

The second number is the objective lens diameter. Many people still believe that you want the second number to be 10 times larger than the first number. However, with the advances in technology look for a number between 30 and 50mm. When a person watching birds increases the number here they will have more light in your image. The person will also have more weight to carry around and the binoculars will be more expensive.

The third factor is the exit pupil size. Look for a number here with a value of at least 4 mm. If most of your birding activity will be in dim light situations consider buying 5 mm plus.

The fourth consideration is the prism. The advantages of the porro prism is that they have a wider field of view, give a brighter picture, and usually costs less. The advantages of a roof prism are that they are lightweight, are waterproof, and are stream-lined.

The fifth major consideration is the users ability to focus quickly and sharply.
These are the five major considerations when buying the best bird watching binoculars.

Since the human eyes and the lens are different the photograph will not always be the same as the view seen through the eye piece. Thus, the quality of the picture depends more on lens size and its zooming capabilities. These features are identified by the binoculars numbers, for example 5 by 35, where 5 is the zoom level and 35 is the size of the lens. Basically the bigger the lens then the better the image.

The only downside of camera binoculars is they have limited memory space. Meaning before any new pictures or streaming video can be stored, the older photographs or video will need to be transferred or deleted. However all camera binoculars are shipped with software that allows you to transfer pictures and video to different types of memory storage. They also come shipped with a USB cable for transferring pictures and videos, a neck strap to help prevent them from being dropped, and a tripod to help against hand tremors.

For the most part camera binoculars are relatively affordable and fun to use. They are great for hunting, fishing, general research, and any other type of outdoor activity. So If your an outdoor enthusiast who wants to take memorable photographs or record lasting videos, then I would recommend buying a pair of camera binoculars.