I have a pair of bino's that have.. well, lets put it nicely, have seen better decades.
Whilst they still work ok at the moment, I'm looking for some experienced advice on what I should be looking at as a potential replacement set for when the worst comes do pass. Ideally for use in both field and target.
I believe my current ones are 10x40
10x40 or 10x42 is a nice general purpose size.
You have many choices.
Currently my pick of binos in the "best for the money" category is the Zeiss Terra's
They just tick all the boxes.
Ease of use, ED Glass, Wide sweet spot, Waterproof, Bright and not stupidly priced.
They are still the only thing on the market that would tempt me to upgrade from my Bushnell Legend Ultra HD's. (The original ones. Not the new series)
You can find them for a wide range of prices on the Internet.
Next choice would be Zen Ray ED2 or ED3's as they're also very nice without a ridiculous price.
If you're going to go look at binoculars yourself, first thing to do is see how difficult they are to use.
I have a set of Pentax 20x50's which suck ass if they're not set up by someone who knows that you should have the eye caps screwed out first.
I've picked up Vortex Binos that were a joy to use and Steiners that were optically beautiful.... once you got them perfectly aligned. And they were pretty critical.
Go through the process here to set up your focus.
Help with Use and Adjust Binoculars
Then rest the binos on something so that they're stationary and pointed at something which fills the entire view and is at the same distance away. Brick walls are ideal for this.
With the middle bit focussed, check to see how much of the rest of the view is in focus. The more you pay and the higher quality, the more of the wall will be in focus.
If you pay enough, you'll get edge to edge. This is evaluating the sweet spot.
Find something like a post or sharp line that is vertical and sweep the view of them with your binoculars. See how much it bends out of straight. This is a basic distortion test. Horizontal line too, if you can find one.
Look up at the blue (or grey) sky. (I've been to the UK..) Look for how bright the image of the sky appears across the view. The image WILL get darker closer to the edges. Some bino's get darker more noticeably than others.
See how much focus adjusting you need to go from the expected ranges you will be looking at.
Regular archery fields are good for this. I've had binoculars that would let you look out to past 250 meters in focus if you were focussed on the 50m target and others which had 70m in focus and past that was tosh. That was pretty educational.
The difference in twiddling the dials was super noticeable. If possible, go for depth of field for close use over picky narrow depth of field ones.
Find something dark against a bright sky and look for purple and yellow fringing. ED glass minimises this. These days I wouldn't have anything other than ED glass because I'm an optics whore.
However, occasionally I find second hand bino's that are amazingly good for non ED glass.
Once you have done a few of these comparisons on different binoculars, you'll have some experience to compare them against each other.
You can be quite suprised how WW2 optics compare to modern varieties. Some British war era bino's I've looked at were really good but for fungus damage.
The thing you will really notice in terms of difference is low light performance, but it's one of the things that most people never bother to try out.
In shady conditions like in amongst trees in a field shoot, good low light performance can let you see things in terms of target areas.
My party trick is pointing my spotting scope at the surrounding hills when they're a featureless black to the naked eye. Then I ask people if they can see "the stump" and guesture up towards the hills.
Of course they can't.
Then they look through the spotter and realise that they can see it clearly a kilometer away.
A 42mm objective lens gives you a LOT more light capturing ability than your pupil. However, the light transmission through various amounts of glass plays quite a part too.