Deal with dew to ensure crisp views

Dew will form when moist air meets a cooler surface. Normal binoculars do not have good dew protection for their front lenses. If you mount them, you can use dew-shields made from plastic or foam sheet, but these are awkward for hand-held binoculars. A common solution is to use a portable 12V hair dryer, which you can run from a battery pack or the 12V socket in a car, as a ‘dew gun’. On very cold nights, moisture that evaporates from your eyes can condense on eyepieces; you can reduce this by folding down the eye-cups to allow better air circulation.