Backlight
How to illuminate the clock face.
—
Luminescent coating. A variant used in pointer dials: the hands, and sometimes the scale, are coated with a “phosphorus” coating that glows in the dark. This method of backlighting is inexpensive and can be used even in low-cost models; in addition, it does not require batteries and is suitable even for mechanical watches. On the other hand, coverage is often not as effective as it should be. The fact is that for work it must be “charged” from the sun or another bright light source, and this “charge” is enough for an average of 5-6 hours, and already in the first couple of hours the brightness of the glow drops noticeably.
— Electronic.
Illumination based on LEDs or other miniature light sources. Usually, it does not work constantly, but turns on and off by pressing a special button; the exception is LED dials (see "Dial Type"). The main advantage of electronic backlighting is efficiency: it is guaranteed to be enough to view the image on the dial. In addition, such systems do not depend on external illumination, in contrast to the luminescent coatings described above. On the other hand, the lighting requires a battery to operate; therefore, this type of illumination is found exclusively in quartz watches (see “Mechanism type”).
— Luminescent coating / electronic. Systems that combine both types of illumination described above. This option is f
...ound mainly among models with combined dials: the hands are coated with a luminous coating, and the electronic backlight is intended mainly for displays and additional scales (and also as a backup option for the hands). The combined backlight is very convenient, however, such watches are somewhat more expensive.
— Tritium illumination. Illumination option found on premium pointer dials. Miniature flasks filled with tritium, a radioactive form of hydrogen, are responsible for the illumination in such models; from the inside, the surface of such flasks is covered with a phosphor, which glows under the influence of tritium radiation. Separately, we note that this radiation does not pose a danger to humans: it does not go beyond the bulb, and even inside its intensity is extremely low. Tritium illumination is expensive, but it is extremely convenient from a practical point of view: "flashlights" work constantly, without batteries and regardless of external lighting, and shine significantly brighter than a conventional luminescent coating. However due to the decay of tritium, they gradually lose their brightness, but this happens very slowly: it takes 12 years to reduce by half, and at least 20 years for the backlight to become useless.Crown protection
A safety plate in the area of the crown ensures that this weak spot is protected from damage and leaks.
The crown protection systems are the guarantors of shock resistance and water resistance of watches.
Diameter (width)
The nominal size of a watch case in diameter (for round cases) or width (for other options, see "Case Shape"). In the most miniature modern models, this size is
21 – 25 mm or even
less, among the largest there are cases of
46 – 50 mm and even
larger.
Larger watches are more convenient in the sense that the dial readings are better visible on them, and it is easier to provide various additional functions in the design. On the other hand, small watches look neater and create less discomfort directly when worn. In addition, female models (see "Gender") are traditionally made more miniature than male ones. So the choice for this indicator depends mainly on the intended specifics of the application: for example, large cases are best suited for outdoor activities and tourism, about
41 – 45 mm in size, for household wear (regardless of gender) — about
31 – 35 mm, and as an accessory to an evening dress, a small watch of
30 mm or less would be more appropriate.
Also note that the size of a compatible strap/bracelet is associated with this indicator — see "Strap Width" for details.
Thickness
The thickness of the watch case. A fairly obvious parameter; we only note that nowadays it is customary to attribute watches with a thickness of less than 7 mm to
ultra-thin models. This design has both aesthetic and quite practical meaning — a thin watch will be useful for those who wear narrow sleeves with tight-fitting cuffs.
Weight
Total weight of the watch. As a rule, it is indicated taking into account the complete strap/bracelet.
The lightest modern watch weighs
no more than 50 g. The most popular models weigh 50 - 100 g, and weight more than 150 g most often means not only a large, but also a fairly advanced device, usually for sports and tourism purposes.
Both light and heavy weight have their advantages: light watches create minimal inconvenience when worn, while massive watches are subconsciously perceived as a solid and reliable device.
