We have been opticians for three generations
in our family, and our activity is targeted on three areas, optometry,
contact lenses and optical instruments.
There are different types of
diurnal binoculars with many different optical, mechanical and waterproof qualities.
Magnification ranges from 6 to 30 times. Magnifications over 10 times cannot be held by
hand and need a tripod. Objective apertures range from 18 mm to 80 mm of diameter. The
field of view is described in degrees (7.5¡) or in meters (145 m. wide for a distance of
observation of 1000 m.). To choose your binoculars, you must know for what purposes they
are intended.
Binoculars for occasional utilization:
These binoculars do not need to be of top quality. A magnification of 7 to 8 x, with
an objective of 30 to 40 mm of diameter will be sufficient.
For heavy duty utilization, in damp
environment, in boats, hunting, etc...: They need to have the highest optical,
mechanical and waterproof qualities. The diameter of the objective must be quite large
with middle range of magnification for a good luminosity. Binoculars of 7 x 50 or 8 x
60 will give good results.
Tripod utilization on static places:
Binoculars
must be of top quality because of their high magnification. Binoculars from 12 to
30 x with objectives of 50 to 80 mm. will give good
results, but they are very large and heavy.
As a general rule, the higher the
magnification, the better the quality needed. The bigger the objective, the better the
luminosity for a specified magnification.
French
