Care and Use of Binoculars
Once you have purchased a pair of binoculars it is well worth knowing how to achieve the best results from them, and how to look after them.
When using for the first time:
- Open or close the binoculars with the hinge to set the eyepieces at the correct distance apart for your eyes.
- Whilst looking through the eyepieces to an object of at least seven metres distant, adjust the centre focusing wheel until the left hand image is sharp.
- Adjust the dioptre ring, which is on or behind the right hand eyepiece, until the right image is sharp.
Both images should now be in focus. After a little practice this procedure will take only a few seconds.
Most binoculars have a scale around the small front cover screw of the hinge with the numbers 60 to 70. This is called the interpupillary distance (IPD) that is calibrated in millimetres between the centre of each eyepiece or the distance between the centre of your pupils. Sixty five millimetres is the average distance for an adults eyes. After adjusting this distance to your eyes you can note the number for future reference.
A blow brush is a very useful accessory when cleaning the external lenses, particularly if you’ve used your binoculars where sand or dust particles are present, obvious locations being by the sea or in the desert. These particles collect around the eyepieces and objective lenses, and if they not removed, ideally with a blow brush, the lenses will without doubt be scratched beyond repair when rubbed with a lens cloth. When you’ve finished using your binoculars, it’s always worth cleaning and drying them before storing in their case. If they are not waterproof and used in extreme damp conditions, condensation can occur internally, but this can be removed by leaving the binoculars in a warm dry place for an hour.