Good binoculars are essential for this course. We encourage you to take the time to obtain a quality pair, one that is sharp and clear and that will serve you well in this program and for years to come. There are literally hundreds of different types of binoculars on the market, so we offer the following guide to help you make an informed purchase.

What do the numbers mean?

On each pair of binoculars is a pair of numbers, such as 7x35 or 10x50.

The first number is the magnification power. Higher numbers = greater magnification. Higher magnification enables you to see more detail but makes the binoculars harder to hold steady and reduces light-gathering (see below). Thus, we recommend 7x or 8x binoculars (9x or 10x binoculars are fine with high-quality optics) but nothing lower or higher. It is usually best to avoid zoom or auto-focus binoculars.

The second number is the diameter of the objective lenses (the lenses farthest from the eye). Larger lenses are heavier but they provide a larger field of view, making it easier to scan. Larger lenses also gather more light, producing a brighter image (see below). We recommend lens diameters within the range of 32-50 mm.

Light-gathering or image brightness is determined primarily by the ratio of lens diameter to magnification power. For example,

Image sharpness is determined by the optical quality of the lenses and their coatings. Generally speaking, higher priced binoculars have better optics and sharper (and brighter) images.

How much should I spend?

As is true of all optical equipment, better quality costs more money. With binoculars, more expensive pairs have better lenses and coatings and so are sharper, brighter, more durable, and sometimes waterproof. Some have a full lifetime guarantee. Generally, with regard to price, here is what to expect:

Which brands are best?

Most companies make a number of different models covering a wide range of quality and price. Nikon, Pentax, Audubon, Bushnell, and Eagle Optics, are affordable and reliable. Swarovski, Zeiss, and Leica are the best but most expensive. If you can afford to buy a better model, do so, it will last for many years.

Where should I buy binoculars?

It is best to start somewhere you can try out different models in your price range, but there are few options for this in Santa Cruz. On the web, we prefer Eagle Optics (, but there are many other good sites.

Thatís about it. Donít hesitate to ask if you have questions. Good luck!