What Is Close Focus In Binoculars?
If you see in the specifications on binoculars the phrase close focus, it means the closest distance the binocular lens can focus on an object and still see it clearly. It’s usual for binoculars that feature close focus to have a low magnification and a small objective lens.
There is a distinct difference between how close you can focus on an object and how large something appears to your eyes. Imagine being able to clearly see the pollen on a flower as opposed to just making the flower appear to be larger. That’s the difference between close focus and making an object appear larger.
Why Close Focus Matters
Close focus is particularly useful for butterfly and moth enthusiasts, as regular binoculars can’t focus clearly on objects below 25 ft. Some birding binoculars can focus down to 10ft, but close focus binoculars usually have a clear image as close as 6ft 6 inches. This is particularly important when trying to determine one species of moth from another.
Many insects look very similar to the naked eye, but through the lens of a close-focus binocular, a whole new world opens up.
There have been recent binoculars that have a close focus of 3 ft but these are specialist binoculars that often have hardly any magnification. Or an extremely narrow field of view.
But close focus is the ability to clearly focus on an object as close as 6 ft or thereabouts. Which virtually means someone as tall as Peter Crouch could stand upright and be able to clearly see his toenails through the lens of his binoculars. Whereas with regular binoculars that image of Peters’ toenails would appear blurry (unfocussed).
Frequently Asked Questions
Having a low close focus value will allow you to see butterflies and moths close up and clearly in focus. However, using the same binoculars will not be very good for long distance viewing.
Most top quality binocular brands have a close focus value of 2 – 4 metres
Close focus is the same as minimum focus distance when looking at the attributes of binoculars.