Rangefinder Binoculars – How Do They Work?

Rangefinder Binoculars – How Do They Work?

 

Best Rated Rangefinder Binoculars

 

What are Rangefinder Binoculars and How Do They Work?

If you know the height of an object, such as a hill or navigation marker (often printed on navigation charts), and can measure the angle to its top using binoculars equipped with a rangefinder reticle, you can calculate your distance from that object.

Many of the best marine binoculars come with a reticle rangefinder, that enable those aboard boats, yachts and other marine vessels to calculate the distances

What is a Rangefinder Reticle?

A reticle (or reticule) is a net of fine lines or fibers in the eyepiece of the binocular, monocular, microscope, scope or other optical device used for sighting and taking other measurements.

Rangefinder reticles are obviously used to calculate the distance between you and an object you are observing, but can also be used to calculate the height of an object or the included angle of a viewed object.

 

How do Rangefinder Reticles work?

There are several systems used to calculate the distance by rangefinder reticle binoculars and scopes. The simplest and most commonly used system involves comparing a scale or measuring marks on the reticle in the binocula field-of-view against a known sized object that you are looking at. The military and hunters refer to this as the Mil-Dot reticle and the formula is known as the Mil-dot formula:

 

Mil-dot Formula

Take the height or length of the object, then calculate the distance away from that object using simple math. You can also calculate the height or length of the object if you know the distance that you are away from it.

 

If you are on your boat and look through your reticle rangefinder binoculars at a house that you knew to be 30 feet tall, and the scale height on the reticle rangefinder reads 40:

Distance = (Height of House / Scale Height) / x1000

= (30′ / 40) x 1000

Distance to the house = 750 feet

Do Rangefinder Reticles Work?

Yes, but in terms of providing an exact distances, they aren’t as accurate or fast as a laser rangefinders, but they can give you a good idea and work over long distances.

How accurate they are depends on the user lining up the target and of course how accurate you are when estimating the height or length of the target. If you know the exact height of the target and line it up very carefully on the reticle, they will be very accurate.

For boating binoculars and other marine uses, reticle rangefinders are in most cases the best solution.

See: Best Rated Rangefinder Binoculars.

 

Related Articles from The Lake Life:

 

Top Rated Marine Binoculars

Top Rated Marine Binoculars

 

Top Rated Marine Binoculars

 

 

Choosing a pair of binoculars for use on a boat can be tough; some choices are better than others. The marine environment combines constant dampness with temperature changes, that can cause the  interior lenses of non–waterproof binoculars to fog. Waterproof construction, with the interior o-ring sealed and filled (charged) with dry nitrogen, combined with flotation in the strap, can protect your binoculars if they fall overboard.

Here are the four top-rated marine binoculars – rated by the people who bought them.

 

Carson 3D Series High Definition Waterproof Binoculars with ED Glass

Waterproof and fogproof – these are the perfect binoculars for hunting, bird watching, camping, hiking, backpacking, traveling, concerts, sporting events and other outdoor adventures.

FEATURES:

  • ED Glass for Sharper and Brighter Images
  • Rubberized armor Coating
  • BinoArmor Deluxe carry case, Neck strap, Shoulder harness, Lens covers and Lens cloth
  • Field of View: 314 feet at 1,000 yards; Eye Relief: 16mm | BAK-4 Prisms | Weight: 1.4 lbs.
  • Backed by America’s best binocular warranty

 

Steiner 8×30 Military/Marine Binocular

Steiner 8x30 Military/Marine Binocular
List Price: $299.99
Price: $199.95
You Save: $100.04
Price Disclaimer
These tough, rugged binoculars are rainproof and fog-resistant, and feature a wide field of view. Their unique auto-focusing feature enables focusing at the increased distances over water.

FEATURES:

  • Rugged binocular with 8x magnification and 30mm objective lens
  • Unique auto-focusing design focuses from 20 yards to infinity
  • Tough rubber-armored housing; long 20mm eye relief
  • Rainproof, fog-resistant construction; wide field of view
  • Measures 6.8 x 2.4 x 4.6 inches (W x H x D); weighs 18 ounces

 

Vanguard Endeavor ED 8420 Binocular, 8×42

Vanguard Endeavor ED 1042 Binocular, 10x42
List Price: $249.00
Price: $249.00
Price Disclaimer
These lightweight binoculars are totally waterproof and fogproof and feature ED glass for high resolution.

FEATURES:

  • ED glass reduces color dispersion to provide high resolution colors and clarity
  • Bak4 phase-coated prisms and fully multi-coated lenses
  • Three stage twist out eyecups with long eye relief and locking diopter ring
  • 100% waterproof and fogproof
  • Advanced lens coatings for enhanced light transmission even in low light conditions
  • Lightweight, open bridge body design with large, precise focus wheel
  • Premium Lifetime Warranty
  • Magnification: 8x, Objective Lens Diameter: 42mm, Field of view: 367 ft/1000 yards, View angle: 7.0 degrees, Near focus: 6.6 feet, Eye relief: 19 mm, Weight: 25.8 ounces

 

Bushnell H2O Waterproof/Fogproof Roof Prism Binocular

Beautifully designed, durable, waterproof and fogproof binoculars made with quality materials and tested extensively to provide quality optics with stunning clarity.

FEATURES:

  • 100% waterproof, O-ring sealed and nitrogen purged for reliable, fog-free performance
  • BaK-4 prisms and multi-coated optics offer crisp clear images with improved light transmission
  • Non-slip rubber armor and Soft Texture Grip absorbs shock and provides a firm grip
  • 10x magnification and 42mm objective diameter; 12-foot close focus distance; 17mm eye relief
  • Large center-focus knob for easy adjustments with Twist-up eyecups
  • Limited lifetime warranty

Related Articles from The Lake Life:

Wear the Correct Water Footwear

Why You Need to Wear the Correct Water Footwear

What is Water Footwear?

Keen Men's Newport H2 Sandal Wear the Correct Water Footwear

Keen Men’s Newport H2 Sandal

As you might expect, water footwear is footwear specifically designed for activities in or around the water. While some footwear is designed for casual use aboard a yacht or large ship, others give traction and safety for sports such as kayaking, river rafting, float fishing, and canoeing. Water footwear is made for people who expect to go in and out of the water often, and who need the benefits these specially designed shoes and sandals offer.

 

 

Different Types of Water Footwear

Here are the basic types of water footwear that people use. They are all designed for different activities. Some are designed for casual use, while others are specially designed for rugged performance in the water.

It is sometimes confusing because manufacturers use the different terms interchangeably The Keen Newport H2 Sandal pictured above is actually considered a water shoe here because of its toe protection and enhanced traction sole. Other manufacturers and distributors refer to their water sandals as water shoes. We will try to stay within the following distinctions here.

 

Merrell Men's All Out Blaze Sieve Water Shoe Wear the Correct Water Footwear

Merrell Men’s All Out Blaze Sieve Water Shoe

Water Shoes: are quick drying, and give the comfort of a water sandal, but also feature the toe protection and traction of a standard shoe. These are the most versatile type of water footwear. The foot and toe protection, combined with the superb traction, makes water shoes the ideal footwear for anyone who climbs in and out of the water often. 

Water shoes are just at home on land as they are in the water. Because they fit like an athletic sneaker, they are comfortable for trail hiking, walking around the mall or other day-to-day uses. Water shoes are the most versatile footwear available for people who take part in active water sports, especially in rocky terrain.

 

Teva Men's ALP Sport Water Sandal Wear the Correct Water Footwear

Teva Men’s ALP Water Sandal

 

Water Sandals: quick-drying and comfortable, water sandals do not offer the added traction and protection of a water shoe. Water sandals are easier to put on than water shoes, and are often much less expensive.

 

Sperry Top-Sider Boat Shoe Wear the Correct Water Footwear

Sperry Top-Sider Boat Shoe

 

Boat Shoes: are comfortable, look great and work well for large boats, and casual wear away from the water. These shoes are not designed for use in the water although they will add traction when walking on a boat’s wet deck.

 

 

 

Wear the Correct Water Footwear Speedo Women's Zipwalker 4.0 Athletic Water Shoe

Speedo Women’s Zipwalker 4.0 Athletic Water Shoe

 

Wet Shoes: these are comfortable and work well in certain situations, but are practically useless out of the water, and offer limited foot protection.

 

 

Teva Women's W Deckers Flip Sandal not the Correct Water Footwear

Teva Women’s W Deckers Flip Sandal

Flip-flops and Slides: these may be comfortable for walking around the house, the pool or at the beach, but they offer the least traction and protection of any water footwear, and are not safe for use in the water, because they might not stay on the foot.

 

 

 

Why You Should Use Water Footwear

Safety and Protection: The proper water footwear is designed to give traction when surfaces are wet or slippery. These conditions can range from the deck of a million dollar yacht to a rocky shoreline.

Most water shoes cover the entire foot and have thick soles to protect the soles of your feet from stone bruises or cuts from shells, sticks or glass, as well as hot surfaces. Styles that have built-in toe shields can prevent stubbed toes.Most water shoes also feature specially designed treads for the most traction on slippery surfaces, including rocks, boat decks, docks and water equipment. Their rubber outsoles also give a better grip on these wet surfaces.

Slip-on wet shoes help guard your skin from the sun while keeping sand off your feet while enjoying a day at the beach.Although slip-on styles are great for the beach and underwater use, they don’t offer the ankle support of their lace-up counterparts, which are better suited for hiking wet trails, streams and creek beds.

Durability:  Because water footwear is designed to not degrade when immersed in water and to not mold, they are more durable than regular shoes.

Comfort and Warmth: Regular shoes become soaked or waterlogged when submerged causing them to become heavy, uncomfortable and prone to causing blisters. Good water shoes or water sandals will be made of well-ventilated fabrics and have multiple drainage points and perforations to help water drain; will not hold water and will dry quickly – making them more comfortable.

 

When to Wear Water Footwear

Water-resistant slides or even flip-flops may be good enough for poolside protection, but water shoes deliver added benefits required for other activities. They also come in different styles. Slip-on water shoes are perfect for a day at the beach and ocean swimming, while lace-up styles offer more support for hiking and more intense outdoor activities. Other variations feature adjustable bungee-cord lacing for the ease of a slip-on and security of a lace-up.

Water footwear is ideal for watersports, such as: canoeing, kayaking and other paddle sports. They should be used for swimming in oceans, lakes and rivers, and they’ll provide foot protection while doing aquatic aerobic exercises or outside of the pool. Boaters and anglers appreciate the secure footing that is provided.

Whether enjoying the beach with your family, paddling down a river or hiking through mountain creeks, be sure to wear your water footwear. The right water footwear will keep your feet protected, drier and more comfortable, so you can enjoy every moment of your time at or in the water.