All About Roof Prism Binoculars

Binoculars use prisms that redirect incoming light in different directions allowing it to travel a long distance in a small amount of space. A long focal length can be used in this way. Without prisms, the sides of binoculars would be as long as telescopes.

Most binoculars use either a porro prism design or a roof mounted design.

Porro prism binoculars use prisms that are offset at a distance from each other giving them their familiar dog-leg appearance. This usually makes them bulky and heavy.

Roof prism binoculars have prisms that are mounted close to each other at a 90 degree angle from each other. This avoids the offset design of porro prism binoculars. Unlike porro prism binoculars, the eyepiece is directly in line with the front objective lens.

This gives them a sleek look and makes them smaller and lighter-weight because large offset barells are not needed. For most people, they are easier to handle and focus..

They are also usually more rugged. With porro prisms the eyepieces moves in and out. In roof prisms the eyepieces do not move.

The objective lenses move within the barrels of the body where they are better supported and protected. When you focus them you will not see any outside movement of the lenses. Also, porro prism binoculars use rubber gaskets to seal the lenses. With the external movement, they eventually wear allowing moisture to enter the binoculars.

Typically, roof prism binoculars have been more expensive because more labor was used to make them. With updated construction methods however, the price of production has greatly been reduced. Now roof prisms with excellent quality can be had for reasonable prices.

Bird watching has been an important part of my life for over 30 years. It's a great hobby shared by people all over the world. It can be enjoyed at any level from observing birds at your bird feeder to taking trips to the park, countryside, or even to resorts catering to birdwatchers. Birds are beautiful, fascinating creatures and observing them can teach you about our natural world.

compared to most other hobbies, bird watching takes little to get started. All you need is a a good birding field guide to help you identify the birds you see and a pair of binoculars. Joining a club like your local Audubon Society is certainly not necessary but it is a great way to meet other birders, learn more about birds and their habitat, and go on sponsored outings.

After awhile, birding will probably peak your interest in other natural sciences. In my case, I've also I've become interested in wildflowers, trees, and even geology.

The purpose of my blog is to help people learn about bird watching and begin an adventure that's fun and will enrich their lives.

Bird Watching in the City

In an email the other day, a friend of mine complained that he was interested in birding but thought his opportunities were limited because he lived in a large city.

Actually, birdwatching can be excellent in cities. One just has to pay attention. Many birds are opportunistic, that is they take what they can get. If a metropolis can provide shelter and food for them, that's often where they will be. Peregrine falcons have adapted to city living where the ledges of tall buildings approximate the cliffs of their natural habitat. In fact, city officials have helped introduce nesting pairs to their towns. Also, every city I know has a large park that several bird species call home. If you live someplace that's on a coast there will be several sea birds waiting to be seen. Put up a bird feeder. Yo will be surprised at who shows up.

A couple of my most memorable bird encounters took place while visiting downtown St. Louis.

Walking around, shopping, and being the typical tourist, I was startled by an American kestral that swooped down seemingly from nowhere and pluck a poor house sparrow from its perch on top of a metal sign, carrying it away in its talons. Later that day, visiting Forest Park, I witnessed two beautiful Mississippi kites trying their best to peck people on the head to keep them away from their nest.

Anyway, the point of all this is to encourage city dwellers to begin birdwatching. The birds are there and you'll see them if you look.

Audubon Chapters

Here is a list of Audubon Society web sites that are available for most states. You can find information about birds, activities, and local chapters in your state.

Joining your local chapter is a great way to meet friendly people who are also
passionate about birds and learn about programs and field trips.

• Alaska http://ak.audubon.org
• Arizona http://az.audubon.org
• Arkansas http://ar.audubon.org
• California http://ca.audubon.org
• Colorado http://co.audubon.org
• Connecticut http://ct.audubon.org.
• Florida http://fl.audubon.org
• Maine http://www.maineaudubon.org
• Maryland-DC http://mddc.audubon.org
• Minnesota http://mn.audubon.org
• Mississippi http://ms.audubon.org
• Missouri http://mo.audubon.org
• Montana Audubon http://www.mtaudubon.org
• North Carolina http://nc.audubon.org
• Nebraska http://ne.audubon.org
• New Mexico http://nm.audubon.org
• New York http://ny.audubon.org
• Ohio http://oh.audubon.org
• Pennsylvania http://pa.audubon.org 
• South Carolina http://sc.audubon.org
• Texas http://tx.audubon.org
• Vermont http://vt.audubon.org
• Washington http://wa.audubon.org
• Wyoming http://wy.audubon.org

Bird Field Guides

If you have never looked for books about bird watching, you will probably be surprised at the number available online and in book stores. There are several good field guides to choose from and every bird watcher has his or her favorite.

The field guides I am writing about are for North America however, there are guides for almost every continent. The Peterson Field Guide Series has an excellent guide for Europe available in several languages.

Some guides use photographs for identifying birds and others use colored drawings. I have used both kinds and each have something to recommend them.

I prefer field guides with drawings or paintings. The artist can illustrate markings, colors, and, patterns that can easily be used for identification. The drawings stress what you need to look for.

Guides that rely on photographs are at the mercy of transitory lighting conditions and random positions of the birds.

The field guides that I have used for years are the Peterson Field Guides to Birds. Both written and illustrated by Roger Tory Peterson often called, " The father of bird watching." They are the, A Field Guide to the Birds of Eastern and Central North America which covers an area roughly from the 100th meridian ( A line running through western Kansas, Nebraska, and the Dakotas ) to the Atlantic states and the, Peterson Field Guide to Birds of Western North America that includes birds west of the 100th meridian.

The advantages to these guides are:

 Wonderful paintings by Roger Tory Peterson that emphasize field marks to look for. Uncrowded pages usually only showing four or five species on a page. -Bird Descriptions on pages directly across from the illustrations. No more thumbing to the

Back of the book looking for notes about the birds. -Maps showing the ranges of each
Bird species.

Another very popular guide is the Golden Field Guide, Birds of North America. This book also has excellent painted illustrations.

Some other field guides I recommend are the National Geographic Field Guide to the Birds of North America, Sixth Edition, National Audubon Society Field Guide to North American Birds-both eastern and western editions, and the National Wildlife Federation Field Guide to Birds of North America.

• Choosing a field guide is a personal decision. Take your time and find the one that works for you.