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”).
Touch control
Touch control is considered more convenient and advanced than buttons, toggle switches, rotary knobs and other mechanical controls. Firstly, the touchpad has a flat surface without protruding parts, making it less dirty and easier to clean. Secondly, there are no moving parts on the panel, which increases its service life. Thirdly, the sensors can perceive different types of actions, which allows you to use one simple panel for different functions: for example, turn a lamp on and off with a short “tap”, and change the brightness by moving your finger up or down. There are also quite unusual functions - for example, “random” color selection depending on where the panel was touched and how many milliseconds it lasted. It is also worth noting that the sensors can have a “technological” appearance, perfect for modern style lamps; and among the “classics” there are models where the stand is one continuous touch surface.
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).
