Battery capacity
Battery capacity for battery-powered models (see Main Power Source).
Theoretically, higher capacity allows for greater autonomy, but in practice, not everything is so simple. At a minimum, the actual charge time will depend on the power of the light source and its power consumption. For example, a conventional model with an 1800 mAh battery will definitely have a longer operating time on a full charge than a table lamp of similar brightness and power with a 1000 mAh battery. But exactly how much higher the autonomy will be is impossible to say for sure. To assess autonomy, it is better to focus on more mundane characteristics - first of all, on the directly stated maximum operating time specified in the technical documentation.
Luminous flux
Luminous flux provided by a lamp. This parameter is indicated only for models using built-in LED modules (see “Light source”) - in lamps with a socket, it will depend on the light bulbs used.
Luminous flux is essentially the brightness of the lamp. The brightness itself in lumens tells little to the average user, a non-specialist; however, there are tables that allow you to compare the luminous flux of a lamp with a particular light source of standard brightness. For example, a 40 W incandescent lamp produces about 415 lm, a 60 W lamp produces 710 lm, and a 100 W lamp produces 1340 lm. More detailed tables for comparison can be found in special sources.
Speaking of brightness, it is also worth noting that it should not be too low or too high: both create discomfort, increase fatigue and can lead to eye problems. Reference sources provide recommendations on optimal brightness for different tasks. However, this point can be determined for yourself experimentally. And if in doubt, you can purchase a lamp with adjustable brightness (see “Functions and capabilities”).
Colour temperature
Color temperature of the light emitted by the lamp. Specified only for models with built-in LEDs (see "Light Source") as different bulbs with various characteristics can be installed in the socket.
This parameter directly determines the shade of the visible color. The physical meaning of this is that as the color temperature increases, this shade becomes more
"cold", shifting from yellow to blue. Here are some examples of color temperature for clarity:
— 1500 – 2000 K — candle flame;
— 2800 K — 100 W incandescent lamp (
warm light);
— 4000 K — fluorescent
daylight white lamp (this kind of light can already be perceived as cool);
— 5000 K — midday sun light;
— 5500 K — shade from white clouds at noon;
And so on, leaning towards blue, cooler shades.
It should be noted that the choice based on this parameter depends not only on personal preferences and design considerations but also on the overall purpose of the lamp. For example, high color temperature (from 5000 K) is considered optimal for reading, medium (around 4000 – 5000 K) is comfortable for mathematical calculations, working with documents, and other tasks requiring concentration, while soft warm light up to 4000 K is good for relaxation and creating a cozy atmosphere. Therefore, many lamps are designed with
adjustable color temperature.
USB charging
Possibility
of charging the battery from a USB port. This function allows you to replace the power cord if necessary if it becomes frayed or lost. And there are advantages to ease of use: the battery can be recharged from the USB port of a power bank or laptop. In this case, the connector in the device itself can be microUSB, USB C, or a proprietary one, which will require an appropriate cable (included in the kit, but replacement will be more difficult).
