Guide To Cleaning Lenses

• Keep cleaning to a minimum. Every time you clean a lens, you run the risk of damaging it. Only clean your binoculars or telescope if you can notice that the image is not as clear as it should be.
• Grains of sand are the enemy as they can easily scratch optical glass. Therefore, before cleaning a lens, remove any grit with a blower or blower brush. Hold the lens facing down, so that any sand grains can drop clear, and pay particular attention to the corners at the edge of the lens.
• When you are certain that there is no grit on the lens, breathe onto its surface to apply a mist of moisture, and using a cloth, clean in a circular motion working towards the edge. Always keep your lens cloth in a sealed bag to avaoid contamination, and never use a handkerchief out of a pocket. Tissues can vary in quality, and unless specifically designed for lens cleaning, are best avoided. When using a cloth, avoid pressing with a finger behind the cloth, as this can apply unnecessary pressure and risks serious damage if a stray bit of grit is still on the lens. It is safer to bunch the cloth to form a pad and apply gentler pressure.
• With stubborn marks, and grease spots such as fingerprints, use lens-cleaning fluid, but not applied directly to the lens. Instead, put a couple of drops of fluid onto the tip of a "cotton bud" and roll the tip over the spot to lift the grease off, rather than smearing it over the whole lens. Finish cleaning the lens by following the steps given earlier.