I’m a K9 handler and deputy working interdiction in Oklahoma, I’ve currently got a set of 20x80 Steiner binoculars but I’m looking to upgrade. The Steiner’s are way too big but I need something clear enough to be able to read car tags going down the highway. I’ve owned some lower power leica and Swarovski optics for tactical and hunting applications but would like to hear some opinions. These Steiner binoculars I’m currently running aren’t anywhere near clear enough to do what I’m trying to do with them.
How is your vision?
At what distance are you viewing?
Are you using hand-held or a mount?
Are you attempting to view through the windshield?
Is it cold, or are you trying to view through mirage?
License plate numbers are what? 2.75” tall in the USA?
Run the numbers-
It’s generally accepted in astronomy that you get full image breakdown attempting 100X from a 1” lens. Most acceptable views come from 1/4 of that or even less. That means if you are using a 50mm lens telescope (2”), you will still get your best imaging at less than 25X, actually much lower due to a few other factors.
Every surface of glass between your eye and the target must be perfectly polished. The more surfaces, the greater the stacking errors. That means every lens surface (front AND rear), every prism surface or mirror surface contributes to degrading the image.
Now, as has been written a bunch, every one of those glass surfaces only allows a portion of the available light to pass through, the rest is lost to reflection. That has been countered by enormous strides in high tech lens coatings, but read the fine print….. It’s not just the exterior lenses that need coating, but EVERY GLASS SURFACE, which is more costly.
Compromises are made.
Perfect eyes are said to be able to resolve a non-self illuminated object of 1” at 100yds. But that plate number is 2.75” tall? Ahh, did you forget the width of the characters? That cuts things down according. An S looks like a 5, and that’s just the start.
Also remember, in your shopping, that lens size effects clarity looking through mirage. A large lens looks through more distortion than a small lens, that boiling target’s surface may seem to stay centered in a large lens, while the possibly sharper view through the small lens seems to dance around more.
Compromises must be made.
I’d recommend discussing this with a birding group if you can, and if possible, visit a store which allows you to try binoculars side by side for comparison.
Along with image clarity, also note brightness and trueness of colors.
Remember the old trick of holding the binoculars/scope at arm’s length away and notice the size of the small disk of light centered in the lens (the exit pupil). Older adult eye pupils only dilate approximately to 5mm at night, compared to 7mm in your youth. 10X50 binoculars generally have an exit pupil of 5mm (50mm objective divided by 10X magnification equals 5mm exit pupil). Of coarse that’s if they added material to that lens size so the UNOBSTRUCTED view is 50mm (it usually isn’t). A large exit pupil is easier/faster to use in dim light, and allows your eye to be less precisely centered and still have a full field of view. Go smaller than what your eye allows and you may miss something or get frustrated.
You don’t always get what you pay for, and sometimes stellar deals can be found.
