The BNISE compact birdwatching binoculars are a budget model with 10x42 optics. They promise high-definition and bright images, but have some shortcomings, as is to be expected from such a cheap model.
The BNISE binoculars are comfortable, lightweight and durable. The aluminum alloy body features anti-slip rubber armor to maintain a secure grip.
The adjustment knobs are easy to reach and operate smoothly. With rotating eyecups, you can use these binoculars with eyeglasses.
The binoculars use quality barium crown prisms for a round exit pupil, however, you get a smaller diameter with this model. Multiple coatings improve light transfer, color and contrast.
The manufacturer does not specify close focus and field of view, but you can expect an apparent FOV of around 50° and a close focus just below 10 feet - average values for a 10x42 budget model.
The binoculars are only water and fog-resistant, but not fully proof. There is no indication of dry gas purging or full sealing.
The BNISE binoculars are the best budget bird watching binoculars but you should treat them carefully to prevent long-term moisture buildup inside and internal fogging.
Bird Watching Binoculars Comparison
How to Choose the Best Birding Binoculars
Size & Weight
Optics
Magnification
Objective Lens Size
Field Of View
Lens Coatings
Waterproofing
FAQs: About Birding Binoculars
In the following guide, we’ll introduce you to the deciding factors when it comes to picking the best binoculars for birding. We’ll explain the most important numbers of optics and how to make a sensible decision since bigger and larger is not always better.
It helps to have some understanding of the distances at which you’ll be spotting birds, and if you’re looking for a more portable model of a higher-performance pair meant for stationary use with a tripod.
If you are a beginning birder, have a look at our How to Start Birding Guide.
How do you decide which model is best for you?
Bird watching binoculars are available in all price ranges and you can spend well over $1,000 for a pair.
Yet more expensive isn’t always better, and depending on how casual or dedicated your birding is, a budget model might be sufficient for you.
The optics are the most important part, with magnification, field of view and close focus. Other important features are coatings for the lenses and how rugged the model is.
Size & Weight
Weight and dimensions are important as you’ll have to carry and hold your binoculars, or want to fit them into a backpack. These factors will largely be influenced by the material of the body, and by the optics.
Smaller binoculars feature lenses with a diameter in the range of 20mm to 28mm. They’re easier to carrier and wield and are great for travel. Yet smaller lenses mean less light and therefore impaired vision, especially during dusk or dawn.
Standard size birding binoculars might feature lenses of 40mm or 42mm, which are very popular. Some prefer full-sized 50mm binoculars and take the heavier weight in favor of brighter image and wider view.
A short lesson in optics: binoculars consist of two aligned telescopes for vision at a distance with both eyes.
They provide the viewer with a three-dimensional image with an impression of depth. Light enters through an objective lens, passes through prisms inside, leaves through the eyepiece and enters your pupil.
The most important numbers for the optics of binoculars are commonly specified like this: 8x40. The first number specifies the magnification power, the second number refers to the diameter of the objective lens.
Binoculars are about magnification, enabling you to see distant things up close. It seems logical that a higher magnification is better. You should buy the model with the highest power.
Yet a higher magnification introduces disadvantages: it will narrow the field of view, reduce depth focus and image brightness, and make it harder to get a steady view.
For a magnification power greater than 10x, you generally need a tripod to get a steady image. A popular value is a 8x or 10x zoom for birdwatching.
This gives you a field of view wide enough to spot birds in trees or in a field. You’ll also be able to keep the image steadier than with 12x or 16x magnification.
Objective Lens Size
The size of the objective lens specifies the diameter in millimeters. Light enters through the objective, meaning a bigger lens gathers more light, resulting in a brighter image.
Yet again, the biggest lens is not always the best way to go. As the size increases, so do bulk, weight, and cost. For a hand-held pair, 50mm are the absolute maximum.
A common rule of thumb for birders is to choose the objective lens size five times larger than the magnification power. Popular combinations are 8x40 or 8x42.
However, due to increased quality in optics and special lens treatment with coatings, you don’t necessarily have to stick to this rule, especially for higher-priced binoculars.
For your standard binoculars, a lens size between 30mm and 50mm is a good choice; anything below 30mm can be considered compact. These are great for travel, but if all you own is a compact pair, your birdwatching experience could be lessened.
Again, the popular sizes of 8x40 and 8x42 offer great compromises between brightness, field of view, and weight.
If you’ll be birding primarily in low-light conditions, that is in dense woods, at dusk or dawn or watching night-active birds such as owls, consider a bigger objective lens for more light gathering capacity.
When increasing the objective lens size, though, keep this in mind: lager lenses are more expensive, and only high-quality ones deliver good results. A solid 40mm lens is more enjoyable than a cheap 50mm lens.
Field of view or FOV for short refers to the width of the image as seen through optics. Birdwatchers generally prefer a wider field of view. There is an inverse relationship between FOV. Magnification: with higher magnification power comes a narrower field of view. On cheap binoculars with a wide FOV, you might notice distortion around the image borders.
A wide enough field of view makes it easier to spot and track birds, especially when they’re moving or hidden in nature. If you can compromise magnification for FOV, it’s a good choice to opt for a wider field of vision.
The FOV can be specified in several ways. An example for “at a distance” would be 300 feet at 1,000 yards. An object in focus 1,000 yards away would therefore have a total image width of 300 feet. An easier reference is the angular FOV or the apparent FOV. An angular field of view could be 6°.
To know the image width in feet, you’d multiply by 52.5: 6 x 52.5 results in 315 feet at 1,000 yards. The apparent field of view is a larger angle. Refers to the FOV as it appears to the human eye at magnification.
Lens Coatings
Higher-quality binoculars feature lens coatings. The optics are treated with additional material to increase their performance. Most common is an anti-reflective lens coating to help transmit light and deliver a brighter image.
Without such a coating, up to half of the light that enters through the objective lens can be lost in passing and never make it into the eye of the observer. With this special treatment, it becomes viable to use smaller objective lenses that perform just as well as larger, untreated ones.
With multiple coatings, manufacturers reduce glare and improve contrast. However, the term “coated” at minimum means a single layer on one lens. “Fully coated” specifies all lenses feature at least one layer. “Fully multi-coated” is the best. Coatings highly influence low-light performance. Are a determining factor when light is less than ideal. You will see that manufacturers specify a “twilight factor” for their binoculars as a way of showing how well they perform in dim light - a higher number is better.
This factor is calculated by multiplying magnifying power and objective lens size and taking the square root. A pair of 10x42 binoculars therefore has a twilight factor of 20.5.
However, two models with and without coating will have the same number if the optics are otherwise identical, yet the model with high transmission coating will outperform the one without.
This becomes very apparent with old binoculars from the 40s or 60s or very cheap models, which perform poorly in dim light.
Most higher-grade birding binoculars can withstand humidity and mild rain. Waterproofed models go further and keep out water and fog with O-ring sealings to be moisture proof.
The sealing or proofing is good to have because it will also keep out dust and dirt. To prevent the lenses from fogging up, good binoculars are gas purged, meaning that inside they feature a dry gas such as Argon or Nitrogen instead of air.
A properly waterproofed and purged pair is resistant to corrosion and will last you longer.
Prism Design
Binoculars feature prisms inside to pass on the light, and there are two different designs: porro prisms and roof prisms. With porro type binoculars, the light path is angled in a Z-shape.
The eyepieces are offset from the objective lenses. The result is a wider pair with the traditional V-shape for binoculars. With porro prisms, binoculars use straight barrels and thus feature an H-shape.
Eyepieces and objective lenses are approximately aligned and the prisms inside overlap closely. This design is more costly, yet it is more durable and easier to seal.
Comparison: Porro vs. Roof Design
Misc Binocular Considerations
Close Focus
The shortest distance at which binoculars can provide a sharp image is called close focus. As the magnification power increases, so does the close focus. So you’ll have to consider how close you can get to the birds you’ll be observing most.
Commonly, you’ll view them at some distance, but a low close focus guarantees that you can still use your binoculars to look at birds in detail when they’re 15 or even only 10 feet away.
Should you want to observe other wildlife such as butterflies at even closer range through your binoculars, you’ll need a very low close focus distance. Again, close focus is a trade-off with the magnification power of birdwatching binoculars.
This term describes the diameter of the image or the dot of light as it comes out of the ocular lens in the eyepiece. A larger exit pupil makes it easier to align the image with the pupil of the eye, especially in low-light conditions.
A smaller exit pupil in daylight is still acceptable. The Exit Pupil is calculated by dividing objective size by magnification power. A 8x42 pair of binoculars therefore has an exit pupil of 5.25mm.
The exit pupil distance is also called eye relief in order to clearly separate it from the exit pupil diameter described above. This value described the distance between the eye. The eyepiece in which you can still see the image.
With a greater eye relief, the pupil of the human eye can be further from the ocular lens and still see the image comfortable. This becomes important when you want to use glasses with your binoculars.
Again, magnification power plays a role in this, as a larger magnification reduces eye relief. If you’re wearing glasses, you’ll find the eye relief on 8x binoculars more satisfactory than on 10x ones. Q: What is birding. Where can you do it?
A: Birdwatching or “birding” means observing wild birds in their natural habitat, identifying species and understanding their habits. In the USA, you can observe more than 800 different bird species.
Birdwatchers use their own backyards and local parks for the activity, or they travel to certain environments such as forests, lakes, nature reserves, national parks or native prairie.
Q: What do the numbers on bird watching binoculars mean?
A: A pair of binoculars typically features a set of numbers, such as 8x42. These stand for the magnification power (8). The objective size of the binoculars. Magnification signifies how much closer or larger an object will appear. The objective size is often specified in millimeters. Refers to the lens diameter. A larger lens is able to gather more light, resulting in more clarity and brightness, which becomes more noticeable with greater distance.
A specification like 6-10x40 refers to a pair of zoom binoculars with a variable magnification power between 6x and 10x.
Q: Are the binoculars with the highest magnification the best?
A: A common magnification power for birders is 7x, 8x, or 10x. With a high magnification, you can get a closer and more detailed look, but you will be reducing your field of view (FOV).
Birds tend to move, and a narrow field of view makes it more difficult to track them. Any pair of binoculars is always a compromise between magnification and field of view.
Q: What is FOV? A: FOV stands for field of view. Refers to the width of an image when seen through optics. It is commonly specified as width at a distance, such as 300 feet at 1,000 yards, which means a width of 300 feet of an object 1,000 yards away.
An angular field of view is another way to specify the same thing, such as 6° or 15°. A wider field of view means it is easier to find. Track objects with less movement of the binoculars. The field of view is inversely proportional to the magnification power.
Q: What are coatings for bird watching binoculars?
A: Birding binoculars can feature coatings for the glass elements to improve the optics. Most commonly, they serve the purpose of increasing the amount of light that is gathered.
With a good coating, it becomes possible to use a smaller size objective and still have sufficient light. A smaller objective results in a lighter. More compact pair of binoculars.
Further coatings help improve contrast, reduce glare and protect the material. “Fully coated” means that all lenses in the optical system have at least one layer of coating. Q: What is the difference between porro-. Roof-prism binoculars? A: Traditional looking binoculars are porro type. Have an angled light path inside. Roof prism binoculars feature a straight barrel that does not angle the light path. They’re more compact, more difficult to construct and therefore more expensive.
Q: Why are zoom binoculars not as suitable for birdwatching?
A: You might wonder why birding binoculars commonly feature a fixed magnification power. Zoom binoculars have optics with a variable magnification, say 6x to 10x or 8x to 12x.
This is achieved by changing the distance between lenses. However, as you increase this distance, the focal length, the amount of light passed on to the human eye gets less and less, resulting in a darker and blurrier image at high magnification.
Zoom binoculars also feature a smaller field of vision, making them less useful for birdwatching.
Q: Can I use birding binoculars with glasses?
A: If you are near- or far-sighted, you can use the focusing mechanism to properly adjust the binoculars for your eyes.
People with astigmatism or other eye afflictions tend to prefer binoculars with a larger eye relief, which is the optimum distance between the ocular lenses and your eyes.
These binoculars are called long eye relief or high eye-point optics. In addition, rubber eyecups than can be rolled down or adjusted might further help you.
Q: How do I clean my birding binoculars?
A: Always consult the owner’s manual for specific care instructions, especially in the case of coated binoculars, and make sure to follow instructions.
Cleaning generally involves gently cleaning or brushing off dust, then cleaning the lenses with a lens cloth and possibly special cleaning fluid suitable for the specific model. The outer material can be cleaned with a soft cloth.
Always take extra precaution not to scratch the optics. You should not take apart your binoculars as you’ll most likely damage them. Anti-fogging models are nitrogen-filled.
If you think there is foreign matter inside of the optics, contact the manufacturer or a local dealer.
Q: What other equipment do I need?
A: A proper binocular cleaning kit is great to have. If your model didn’t come with a case, you should consider a protective casing to prevent damage or scratches.
For extended stationary sessions or larger, heavier birding binoculars, a tripod can be useful. Mounting your binoculars onto a standard tripod commonly requires and L-shaped adapter.
Q: What are the best binoculars for bird watching?
A: It depends on your budget. If you can afford the extra money, Zeiss and Leica are world renowned for the quality of their optics. However, most of them cost over $1,000. Probably the best bang for your buck would be with the Vortex Optics or the Nikons.
Q: What is the best magnification with binoculars?
A: There is no single answer to this question. Here are a few things to keep in mind. If you will not be able to get close up to your subject, a higher magnification is better like 10x or 12x. Keep in mind the higher the magnification the more “shake” you will get and a tripod will help out greatly. If you are just looking out your back window at a bird feeder, a 6 or 8x magnification should be sufficient.
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