Choose high quality lenses
Choosing binoculars with larger lenses is important because they collect more light and thus give you sharper images.
In poor light conditions, you will need a lens diameter of about 50 mm to improve your field of view, so use this as a guide. The lenses also need to have a good coating, such as an anti-reflective coating, to reduce glare that may obstruct your view.
Consider magnification
Obviously, if you want to take advantage of the long-distance view, you need to have higher magnification.
However, keep in mind that the more magnification you get, the smaller the field of view you have, so if you are focusing on an object rather than needing to track its movement, then it is best to choose a higher magnification.
Select autofocus
This feature will make your life easier because you won’t have to focus on the target manually.
That said, if you prefer to focus manually, for example because the autofocus feature of binoculars can sometimes focus on targets you don’t want to focus on, then this is something to look for in rangefinder binoculars.
Don’t forget eye relief
Eye relief is important in rangefinder binoculars because it will make viewing more comfortable. It will also open up your field of view because the eye relief is the distance from the outer surface of the eyepiece to the position where the eye point is formed.
Basically, if your eyes are outside this distance, you will not get a full field of view. Look for an eye relief of about 15 mm.
Choose a sturdy construction
You will be using rangefinder binoculars outdoors, so you want to make sure they are made of a durable material, such as a rubber case. They should also be waterproof to handle harsh conditions.