What is Magnification?
Magnification is the degree to which the object is enlarged. This holds true with nearly any type of hunting optics, including Binoculars, Spotting Scopes, and Rifle or Shotgun Scopes. With a 7x35 Binocular for instance, the object will appear to be seven times closer than without the aid of Binoculars. The number immediately following the "x" is the diameter in millimeters of the objective (front) lens, again similar with Binoculars, Spotting Scopes and Rifle Scopes. The larger the front lenses the more light that is allowed to enter the Optics. A 10x50 Binoculars has 10 times magnification with a 50mm objective lens.
What is the Objective Lens?
With a 7x42 The number immediately following the "x" is the diameter in millimeters of the objective (front) lens or the light receiving end of the optics. The larger the front lense the more light that is allowed to enter the binocular. A 10x50 Binoculars has 10 times magnification with a 50mm objective lens.
How do you focus your binoculars?
Individual eye strengths vary. Please refer to the instructions included with each type of binoculars.
In general however, CENTER FOCUS and INSTA-FOCUS are the two standard types of focus.
Center Focus Models
1. Adjust the interpupillary distance.
2. Set the diopter setting (normally on the right lens) to zero and view a distant object.
3. Keep both eyes open at all times.
4. Using a lens cover or your hand, cover the objective (front) lens of the side with the diopter setting ring.
5. Using the focus adjustment, focus on the distant object being viewed.
6. Cover the other objective lens and view the same object as above.
7. Using the diopter setting adjustment ring, focus on the same distant object.
8. Your binoculars should now be adjusted for your eyes.
Make a note of the diopter setting for future use. - Notes: Zoom Binoculars should be focused at the highest power possible.
Perma-Focus Binoculars do not require adjustment and use your eye's own ability to accommodate. Most users have no difficulty with these models.
What is the field of view?
The field of view is the width, measured in degrees or feet, of the viewing area you would see at 1000 yards. Field of view is generally affected by the power of the binocular compared to the objective lens size. A larger power (if the objective lens size stays constant) will lead to a reduced field of vision. A larger objective lens (if the power stays constant) will lead to a larger field of view.
What is eye relief?
The distance between your eye and the eyepiece is called "eye relief." Holding true with most optics, extended eye relief is one of the three most critical performance factors, along with magnification and field of view, especially for those who wear eyeglasses in the field. It is extremely important to set the eye relief of the optics to fit your eyes when you draw your weapon up to your shoulders, you must have a full diameter view of the image, as well, when you lift your Binoculars to your eyes, eye relief must be adjusted so that you have a full view image. For example, when you lift your rifle to your shoulder and look through the scope and all you see is a very narrow tunnel to the image, like looking through a drinking straw, your eye relief is not set properly. You must adjust the eye cup, either in or out, to gain the best relief for your eyes, on your weapon.
