Orion warranties against defects in materials or workmanship for a period of one year from the date of purchase for Orion brand products. This warranty is for the benefit of the original retail purchaser only. During this warranty period Orion Telescopes & Binoculars will repair or replace, at Orion’s option, any warranted instrument that proves to be defective, provided it is returned postage paid to: Orion Warranty Repair, 89 Hangar Way, Watsonville, CA 95076. If the product is not registered, proof of purchase (such as a copy of the original invoice) is required. This warranty does not apply if, in Orion’s judgment, the instrument has been abused, mishandled, or modified, nor does it apply to normal wear and tear. This warranty gives customer’s specific legal rights, and you may also have other rights, which vary from state to state. For further warranty service information, contact: Customer Service Department, Orion Telescopes & Binoculars, 89 Hangar Way, Watsonville CA 95076; (800) 676-1343.
Some items may be covered by a warranty period shorter or longer than the standard one year warranty. Specific warranty information is available on the product detail page of the website.

Hiking If you hike or travel a lot, you’ll want a binocular that is compact and lightweight, perhaps even weatherproof. An 8x24 or 10x25 would be a good choice. Birding The most popular model for birdwatching is 8x42. It’s small and nimble, offers steady hand-held views, and has sufficient light grasp to provide bright, well-resolved images. If you plan to study birds at close range, look for a binocular with a near-focus distance of a few feet. Astronomy For stargazing, light grasp is the most important factor. Choose a binocular with at least a 50mm aperture. A 7x50 model is easily hand-holdable and provides nice, wide-field views. The higher-power 10x50 is also popular, and in fact is preferable to the 7x50 where skyglow is a problem. A tripod is recommended for a steady view, however. “Giant” binoculars of 70mm, 80mm, or 100mm aperture will reveal fainter deep-sky objects and more subtle detail. If you can afford the higher price (and a good tripod) and don’t mind the extra bulk.

Binocular sizes are expressed with two numbers: 7x35, 10x50, etc. The first number is the magnification (or power), the second is the aperture, or diameter of the objective (front) lenses in millimeters. For example, 7x35 binoculars provide 7-times magnification and have 35mm objective lenses. For a given magnification, larger objective lenses yield a brighter image in dim light, but also result in a bulkier, heavier binocular.

It is all about brightness.
The exit pupil size determines the amount of light available to the eye. The pupil of your eye widens and contracts depending upon the available light conditions. If the exit pupil of the binocular is as large, or larger than the pupil of your eye, you will see an image as bright as your pupils will allow. The exit pupil is equal to the diameter of the objective lens divided by the magnification. Example: 7x35 binocular, 35 divided by 7 = 5mm. A 3mm exit pupil is sufficient for daytime use, a 5mm is suitable for daytime & twilight, a 7mm is desirable for maximum nighttime or astronomy use.