What Is The Bridge On Binoculars?
A pair of binoculars consists of two barrels joined in the middle by a hinge assembly. That middle bit with the hinge assembly is commonly known as the bridge.
The bridge is where you will find the focussing mechanism and the hinge allows you to move the barrels to fit the distance between your eyes for a more comfortable fit.
What Are The Different Types Of Binocular Bridges?
As binocular designs have changed over recent years, it can be more and more difficult to tell which bridge design is being used on any particular model. They range from;
Closed Bridge
The majority of Porro prism and roof prism binoculars share this design. It is the most common design for binoculars and often features one large hinge that makes the binoculars bulky.
This design provides strength and durability and has a strong, robust feel and look. A typical example of a closed bridge is the Yukon Advanced optics Sideview model.
Closed bridge binoculars can have either a single or double hinge system. The closed bridge can be large and bulky and has no open spaces at all. A typical example is these Bushnell Prime binoculars.
The single hinge bridge system is associated with traditional closed bridge binocular design like these larger Delta optical titanium binoculars or these smaller Zeiss Victory Pocket binoculars.
What Are The Pros & Cons Of Closed Bridge Binoculars?
The main advantages of closed bridge binoculars include:
1.Durability
2.Concealed hinge
3.Stronger, more robust design
4.Often cost less than open bridge binoculars
5.More suitable for smaller hands
6.Can feature single or double hinges
7.Offer better close IPD range
The main disadvantages of closed bridge binoculars include:
Often bulkier than open bridge models
Typically heavier than open bridge models
Double Hinge Bridge
Typically, double hinge binoculars are associated with open bridge designs. But many compact binoculars employ double hinge bridges but with a closed bridge design. A typical example is the Hawke Endurance ED.
Having a double hinge system on a closed bridge allows you to fold the binoculars into an even more compact shape for easy packing and placing in a pocket.
With that said, double hinge, open bridge binoculars have become more widespread in recent years.
Open Bridge
Also referred to as the double hinge bridge because both barrels are connected with two hinges with an open space between the barrels, these types have enough space between the barrels to wrap your hands around. A typical example is the SIG Sauer ZULU7 binoculars.
In many cases there is a connecting piece between the barrels at the objective lens end to help stabilise and balance the weight of the frame. This connecting piece is also where the tripod adapter is fitted.
Even compact binoculars can feature this open bridge design as can be seen here with these Sig Sauer ZULU3 binoculars.
What Are The Pros & Cons Of Open Bridge Binoculars?
The main advantages of open bridge binoculars include:
1.A slimmer profile
2.Reduced overall weight
3.Easier to carry for small hands
4.Easy wrap around grip for both hands
5.Comfortable ergonomic handling
The main disadvantages of open bridge binoculars include:
1.Often cost more than closed bridge models
2.Some consider the open bridge look unappealing
Modern Single Hinge
Since the introduction of the open bridge style binoculars, there have been many style innovations in single hinge models. These have the hinge and focussing assembly positioned higher up the barrels.
This style allows the easy double handed wrap around grip offered on open bridge models but doesn't allow for the stabilising effect of that extra hinge assembly further up the barrels
So Which Design Is Best: Open Or Closed Bridge Binoculars?
In all honesty, there are really good advantages in both designs. Closed bridge binoculars feel more robust and as they are traditionally designed, they appeal to older users because that's what they're used to.
Having said that, there are some really top quality open bridge binoculars available out there which can be more convenient to use. They weigh less, and have a balanced frame which is easy to hold for extended periods.
Closed bridge binoculars are better if you prefer wearing your binoculars on a strap and don't intend to hold them for long periods. Plus many modern closed bridge binoculars are lightweight and more ergonomically designed nowadays.
So in reality it comes down to personal preference and how much you can afford. Whatever style you choose, the one thing you should never skimp on is quality. Always plump for the best glass quality you can afford.
If you decide on binoculars with an open bridge or a closed bridge, always check the optics to make sure you get the best out of your purchase.