Luminous flux (brightness)
The conditional "amount of light" produced by a light bulb in normal mode. The higher the luminous flux, the brighter the light and the more clearly the illuminated scene will be visible. Note that lumen values are used primarily for special purposes; in everyday life, the estimation of brightness by the analogue of LON is more popular (see above), and here the ratio is as follows:
— 40 W analogue LON corresponds to a brightness of 370 lm;
— 60 W — 550 lm;
— 75 W — 800 lm;
— 100 W — 1200 lm;
— 150 W — 1900 lm;
— 200 W — 2700 lm.
Note that the principle "the more the better" in the case of the brightness of light bulbs is not always applicable. And the point here is not only energy consumption: too bright light is harmful to the eyes, leads to rapid fatigue and psychological discomfort.
Colour temperature
This parameter describes the general coloration of the light of the lamp in "warm" or "cold" tones.
Initially, colour temperature is the temperature (in kelvins) of an object at which it begins to glow in a certain colour. Interestingly, the higher its value, the more “cold” the colour is: for example, the dull red glow of a heated metal corresponds to 800-1000 K, and the bluish-white tint of a fluorescent lamp corresponds to about 6000 K.
The temperatures encountered in modern light bulbs can be described approximately as follows:
2700 – 3000 K — "warm" white light, similar to traditional incandescent lamps;
3000 – 3500 K — "slightly warmer than average";
3500 – 6000 K — neutral white, similar to daylight;
More than 6000 K — cold shades of white.
Note that the colour temperature is not directly related to the quality of colour reproduction provided by the light of a particular lamp — much depends on the features of its design and, accordingly, the spectral colour balance.
Scattering angle
The angle of light dispersion is the space in front of the light bulb, which is illuminated by the source itself, and not by the light reflected from the walls and interior items. In other words, the angle of light scattering determines the zone of the best illumination. Classic incandescent bulbs demonstrate the widest dispersion angle — they shine almost 360˚. LED spotlights have the smallest illumination angle, which are able to illuminate well only the area directly under the bulb — the scattering angle in such cases is about 15˚. Of course, a large angle of light scattering is not always needed. Working in the evening at the table, you need light only in front of you, so as not to disturb anyone. For spotlights that light up only small objects in front of them (a painting, sculpture, bas-relief, etc.), the scattering angle can even be from 4 °. As for the top (general) lighting, in this case it is better to choose something with a wider dispersion angle. These bulbs provide extremely uniform illumination.
Brightness control
This category includes all lamps with the ability to
adjust the brightness.
The simplest and most common variety is the so-called dimmable lamps. They are compatible with external regulators (dimmers), but they do not have their own control systems, and when installed in a luminaire without a dimmer, it is impossible to control the brightness of such a lamp. At the same time, such models are only slightly more expensive than non-dimmable counterparts.
A more advanced option are RGB LED lamps (see "Type") with remote controls (see below). In such models, brightness control is carried out using a built-in converter, and an external dimmer is not required; however, such equipment is expensive.
