The Ultimate Guide to Focus Free Binoculars

 

 

 

Autofocus Binoculars Need No Adjustment

The distinguishing feature of binoculars with autofocus is that you do not need to adjust the focus.

Such autofocus binoculars produce sharp image at a distance of several meters to “infinity” (the minimum focal length of the binoculars depends on the magnification power of the binoculars and can be from 10 to 30 meters).

However, such binoculars do not have a diopter adjustment on the right eyepiece.

Usually I recommend to buy focus free binoculars to those whose second hand is busy while observing an object or they observe moving objects and it becomes difficult to continuously adjust the focus.

In short, focus free binoculars allow you to observe objects starting from about 30 feet and whatever you observe will remain in focus.

These are usually hunters, travelers, spectators at various shows and competitions.

 

 

 

Auto Focus Binoculars: Technical Features

The binoculars focus with a free focus is adjusted thanks to accommodation of human’s eye.

This effect is explained by the fact that the crystalline lens of human’s eye is the lens that creates an image of an object on the eye’s retina.

The relaxed lens of a normal, healthy eye sharply depicts objects far enough away from the observer.

For sharp observation of nearby objects, from a few meters or closer, the crystalline lens of human’s eye changes its surface curvature and focal length due to the strain of the eye muscles, that is, it adapts the image for your eye.

Thus, binoculars with autofocus build so called imaginary image for human’s eyes.

 

 

What are Free Focus Binoculars Designed For?

Autofocus binoculars are convenient to use when:

– Observed object is moving fast
– You observe objects while moving
– You don’t know exactly where to expect the appearance of the object to observe
– You need to hold the binoculars with one hand
– You are wearing thick gloves

 

Therefore, such binoculars are ideal for observation:

– For sports competitions, car racing or other sporting events
– For birds when walking in nature
– For animals on a safari
– During walks or trips in the cold periods of the year
– If you are a real or a photo hunter

 

 

 

Autofocus Binoculars: To Buy or Not To Buy?

Binoculars with autofocus is a fairly common version of devices with high-quality optics.

With the help of such binoculars it is interesting to observe objects that are located at a great distance from you.

In this case, the picture is not distorted, which is important.

With the help of such binoculars you can make many interesting things and even discoveries.

As was explained above, the clarity of the image produced by binoculars with autofocus does not require additional adjustment.

The autofocus system makes it possible to observe objects that are more than twenty meters away from you.

The device with high-quality lenses provides a magnification power of up to 50 times.

But I have never seen autofocus binoculars with magnification higher than 15x. The optics have several types of special coating.

This is an anti-reflection coating that is applied to the surface of the lens to reduce the loss of light reflected from lenses.

The less light is lost, the sharper and brighter the image will be, even if it is dark outside.

If you have binoculars and observe objects from time to time you probably by now already know that binoculars allow you to see details that you can’t see when it is dark or even during fog.

All this becomes possible thanks to multiple levels of lens coating.

Modern binoculars are equipped with soft rubber eyecups that cut off excess light and protect your eyes.

This makes image even brighter and more colorful.

 

 

 

Advantages of Focus Free Binoculars

Autofocus binoculars have several advantages:

– It is convenient to hold the binoculars with one hand
– It easily focuses on an object in motion
– Image quality does not change when moving during observation
– Autofocus binoculars are cheaper than standard binoculars

 

 

Focus Free Binoculars VS Standard Binoculars

Autofocus or focus free binoculars are much easier to use because compared to standard binoculars you can use them without any adjustment.

You take binoculars and look through them. Vision is adjusted automatically in combination with your eyes ability to adjust the vision.

Such binoculars are especially good and suitable for old people, children or anyone who doesn’t want to mess with binoculars’ adjustment mechanism.

Such binoculars are lightweight because don’t have moving parts and tend to be cheaper than standard binoculars.

 

 

Focus Free Binoculars VS Individual Focus Binoculars

Sometimes some people may get confused when choosing binoculars due to specific terminology used when describing binoculars.

Free focus binoculars are different from individual focus binoculars. Individual focus optical instruments have two diopters, for each eye separately.

Vision for each eye is adjusted separately like in marine or military binoculars. Such binoculars don’t have central focus knob.

Only two diopters, for the left and right eyes are adjusted to get the clear vision.

Free focus binoculars have neither central focus knob nor diopters for the right and left eye.

You look through focus free binoculars or self-focusing binoculars without any adjustment.

 

 

 

Recap of Technical Features of Focus Free Binoculars

The binoculars’ autofocus system is based on the principle of accommodation of human’s eye.

Accommodation is the ability of the eye to adapt and provide a clear perception of objects located at different distances from it.

When looking through binoculars with autofocus and observing near and far objects, it will itself adjust the focus, i.e. your vision to the changed distance, and the picture will always be in focus.

The optimal field of application for binoculars with autofocus is the observation of fast-moving objects.

In this case, automatic focusing will allow the binoculars to instantly rebuild the image and save a clear and bright picture for you.

This device is perfect for observers who do not want to spin the focus wheel all the time – autofocus will do everything for you.

 

 

When you Should Avoid Focus Free Binoculars

Focus free binoculars rely on the flexibility of human’s eyes so that the image produced by binoculars can be always kept clear and in focus.

For young people it’s not a big problem. When it comes to people over the age of 45, focus free binoculars can cause some strain on their eyes.

That’s why if you plan to buy focus free binoculars and your age is over 45, you better first try it and see how you feel after 10 minutes of using it.

If you plan to look through binoculars for extended periods of time, I think you better choose standard binoculars rather than focus free optical instruments.

 

 

    Orion 4×21 Super-Wide Angle Binoculars

• – Extra-wide field of view binocular
• – Magnification power 4x
• – Field of view: 18° (950 ft at 1000 yards)
• – BaK-4 prism
• – May be not suitable for eyeglass wearers
• – 100% customer satisfaction
• – Price: $79.99

 

 

 

 

 

 

    Bushnell 4×30 Spectator Sport Black, Perafocus

• – Wide field of view 17.1° (900 ft at 1000 yards)
• – Magnification power 4x
• – BaK-4 prism
• – 70% customer satisfaction
• – Price: $85

 

 

 

 

 

 

 

    Steiner Nighthunter 8×56 Binoculars

• – Wide field of view binocular
• – Magnification power 8x
• – Field of view: 8° (421 ft at 1000 yards)
• – BAK-4 prism
• – Waterproof/Fog proof
• – Fully Multicoated
• – Customer satisfaction: Yes
• – Price: $387

 

 

 

 

 

 

 

 

   

Bushnell Spectator 4x30mm Extra-Wide Binocular specifications:

– Magnification: 4x
– Objective diameter 30mm
– Eye relief 10mm
– Exit pupil 6mm
– BAK-4 porro prism
– Fully multi-coated optics
– Rubber fold-down eyecups
– Focus system: Free
– Field of view: 17.1° (900 feet / 1000 yds)
– Customer satisfaction 80%
– Weight 481gr.
– Not tripod adaptable
– Price: $49

 

 

 

 

 

     Steiner 280 Military/Marine 8×30

• Autofocus function
• Field of view 362 feet / 1000 yds or 6.9°
• All-Weather Reliability
• Rubber Armoring
• Unmatched Clarity and Durability
• Autofocus
• No receipt required lifetime warranty
• Rainproof, fog-resistant construction
• Suitable for eyeglass wearers
• Customer satisfaction: 95%
• Price: $299

 

 

 

 

 

 

 

     Steiner Navigator Pro 7×30

• Magnification 7x
• All-Weather Reliability
• Rubber Armored
• Image Clarity
• Durability
• Sports Autofocus system
• Fully multicoated optics
• No receipt required lifetime warranty
• Water proof Fog proof Shock resistant
• 370 feet / 1000 yds or 7°
• Customer satisfaction: 100%
• Price: $245

 

 

 

 

 

 

 

     Steiner Tactical Marine binocular 10×50

• Magnification 10x
• All-Weather Reliability
• Rubber Armored
• Image Clarity
• Durability
• Sports Autofocus system
• Steiner’s advanced lens coatings
• No receipt required lifetime warranty
• Rain proof /Fog proof
• Shock resistant
• 302 feet / 1000 yds or 5.7°
• Customer satisfaction: 89%
• Price: $469

 

 

 

 

 

 

 

Bushnell Spectator Binoculars 8×32 roof prism

– Magnification: 8x
– Objective diameter 32mm
– Eye relief 13mm
– Exit pupil 4mm
– BAK-4 roof prism
– Multi-coated optics
– Twist-up eyecups
– Field of view: 7.3° (382 feet / 1000 yds)
– Waterproof IPX4
– Fogproof
– Customer satisfaction 80%
– Weight 430g.
– Price: $72

 

 

 

 

 

 

 

Bushnell Spectator Binoculars 7×35 porro prism

– Magnification: 7x
– Objective diameter 35mm
– Eye relief 15mm
– Exit pupil 5mm
– BAK-4 porro prism
– Multi-coated optics
– Twist-up eyecups
– Field of view: 9.2° (488 feet / 1000 yds)
– Waterproof IPX4
– Fogproof
– Customer satisfaction 80%
– Weight 726g
– Price: $72

 

 

 

 

 

 

Bushnell Spectator Binoculars 10×40 roof prism

– Magnification: 10x
– Objective diameter 40mm
– Eye relief 14mm
– Exit pupil 4mm
– BAK-4 roof prism
– Multi-coated optics
– Twist-up eyecups
– Field of view: 5.8° (305 feet / 1000 yds)
– Waterproof IPX4
– Fogproof
– Customer satisfaction 90%
– Weight 563g.
– Price: $103

 

 

 

 

 

 

 

Tasco 8×32 Focus Free Binoculars

– Magnification: 8x
– Objective diameter 32mm
– Eye relief 12mm
– Exit pupil 4mm
– Roof prism
– Fully coated optics
– Fold-Down Rubber Eyecups
– Field of view: 7.3° (383 feet / 1000 yds)
– Anti-Reflection Fully Coated Optics
– Fogproof
– Exit Pupil Diameter 4mm
– Customer satisfaction 75%
– Weight 397g.
– Price: $45