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
The colour temperature of the light emitted by the lamp. It is indicated only for models with built-in LED (see "Light source"), since bulbs with different characteristics can be installed in the socket. In luminaires with
colour temperature control(see "Features"), the minimum value is usually taken into account.
This parameter directly determines the hue of the visible colour. At the same time, its physical meaning is such that as the colour temperature rises, this shade becomes more
“cold”, shifts from yellow to blue. Here are some examples of colour temperature, for clarity:
— 1500 – 2000 K — candle flame;
— 2800 K — 100 W incandescent lamp (
warm light);
— 4000 K — a fluorescent
lamp of daylight white light(such light can already be perceived as cold);
— 5000 K — the light of the midday sun;
— 5500 K — a shade from white clouds at noon;
And so on, thickening to blue cold shades.
Note that the choice for this parameter depends not only on personal preferences and design considerations, but also on the general purpose of the lamp. So, a high colour temperature (from 5000 K) is considered optimal for reading, an average colour temperature (about 4000 – 5000 K) is comfortable for mathematical calculations, working with documents and other tasks that require concentration, and
...soft warm light up to 4000 K is good for relaxing and creating atmosphere of comfort.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).
