Olympus 8x42 EXPS I Binoculars on clearance. Cheapest local price elsewhere seems to be $299.
Designed for powerful performance in the great outdoors, the EXPS I series feature fully multi-coated lenses and BaK-4 prisms so whether you're watching a bird in flight or simply checking out the surrounding terrain, you'll be provided with outstanding light gathering power for bright, clear images and viewing at any time.
- High index prisms ensure bright crisp edge-to-edge images
- Ideal for hiking, birdwatching & sports
- Adjustable eye pieces & UV filter
No idea what the numbers meant so found this to share for similar dummies :)
Binocular Magnification
Of the two numbers in my “8x42” example, the first number is its magnification.
Binocular magnification is sometimes referred to as power, I will just use the term magnification. You will notice the “x” alongside the “8” in my example, this belongs with the number. Meaning “8x” or eight times magnification.
Objective lens size
Of the two numbers on my “8x42”, the second indicates the diameter of the main objective lenses, in millimeters.
Objective Lenses on the Opticron Traveller BGA ED 10x32 Binoculars
Using the same examples, an 8x42 binocular has 42mm diameter objective lenses.
Whereas 8x21 has 21mm objective lenses, although with the same 8x magnification.
Comparing 6x21, 8x21, 8x40, and 10x42. These have objective lenses with diameters of 21mm, 21mm, 40mm, 42mm.
Why is this Important?
The surface area of the objective lens captures light from the scene and transmits it to the ocular lens (which then transmits that light to your eye).
A larger objective lens captures more light and so the image seen is potentially brighter than on a smaller one.