Birdwatching Dot Com









The Binocular Advisor

The Scopes Advisor

Sign up for our FREE Email Newsletter


For Bird Watcher's Digest, September 2011

by Michael and Diane Porter

Michael and Diane Porter wrote the following review, which appeared in the September, 2011, Bird Watcher's Digest. It discusses the necessary design principles of a binocular-camera. It also gives an in-depth look at the Bushnell Image-View SyncFocus binocular-camera.

The heart of the camera

The sensor is the heart of every digital camera. It’s the small, rectangular piece of electronics that the lens focuses its image onto. It’s made up of millions of tiny light-sensitive rectangles, called pixels. Each pixel’s job is to convert the intensity of the small bit of light falling onto it into an electrical voltage, so that voltage can be converted to a number. The numbers get stored as picture data and are used later to recreate the image. The number of pixels on a sensor is a measure of its resolution and relates to the amount of detail that the sensor can capture.

A sensor with lots of pixels is good for bird pictures. The extra resolution allows you to later crop the image so the bird fills the frame but retains plenty of sharp detail.

Sensors come in various sizes and with various numbers of pixels. It’s possible to manufacture a smaller sensor with just as many pixels as a larger one. However, as the size of the pixels gets smaller, their ability to accurately measure the light falling on them also diminishes. This loss of accuracy becomes problematical when we want to capture very short intervals of time—like when we need fast shutter speeds to photograph birds.

On most cameras, you can increase the shutter speed by boosting the sensitivity of the sensor. You do that by turning up the ISO setting. However, if you increase the ISO setting too much, you start getting noise artifacts in your pictures, like grainy-looking skies.

A larger sensor, with larger pixels, will allow shorter exposures without causing that grainy look. The problem for binocular-cameras is that a larger sensor requires a larger lens. The lens has to be big enough to create an image that fully covers the sensor. That’s why you see those fat, long lenses on the sidelines at football games where photographers, like birders, are trying to capture close-ups of subjects in motion far away.

Also, it’s a principle of optics that the resolution of a lens is directly proportional to its diameter. You can see this when you test birding scopes. An 80mm scope will clearly outperform a 60mm scope of the same quality. The lens on this camera-binocular is small. The SyncFocus lens diameter is 12.5 mm. In contrast, the diameter of the front lens of the Canon EF 100-400mm f/4.5-5.6L is about 65 mm.

Of course, these are the limitations of current technology. But let's take a look at what the future holds.

NEXT: What's coming in the future?

12 | 3 | 4  | 5 | 6 | Next Page



Need help
choosing binoculars?

The Binocular Advisor



Birdwatching Dot Com

Please call us toll free 800-779-7256 for advice on choosing binoculars or other birding products.
FAX 641-472-7256
Birdwatching Dot Com Store
2197 236th Blvd.
Fairfield, IA 52556

All text and photos copyright Birdwatching Dot Com.