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).
Body / dome material
The material from which the body and/or lampshade is made.
— Plastic. Inexpensive and at the same time quite practical, thanks to which it is a popular material. Plastic can have any colour and transparency, parts of even complex shapes are easily made from it, plus such products weigh a little. The disadvantage of this option is considered to be relatively low strength; however, in the case of table lamps, it is quite enough for normal use, and even in case of various household "troubles" such as falling from the table to the floor. Plastic as a whole poorly resists scratches — but this point is purely aesthetic, and besides, a lot depends on the specific type of plastic.
— Metal. A common name that combines several types of alloys. It is indicated when the manufacturer, for one reason or another, decided not to specify the composition of the metal used for the lamp. Anyway, such cases and shades are noticeably stronger and more reliable than plastic ones, but they are more expensive and, in most cases, weigh more.
— Steel. Steel can be used in both advanced and relatively inexpensive table lamps. In the first case, the product is often made of "stainless steel" and has a polished surface; in the second, simpler grades of steel with paint or other protective coating can be used. Anyway, this material is durable and cheaper than aluminium, but it also weighs noticeably more.
— Aluminium. This material can be attributed to the pr...emium class. Aluminium combines the strength of steel and the low weight of plastic; in addition, such cases and shades can have a rather stylish and rich appearance, they are great for high-tech lamps. The disadvantage of this material is traditional — a rather high price.
— Glass. A material used primarily in decorative lamps and candle lamps (see "Type"). Glass can be transparent or translucent, have different colours, be complemented by various relief decorations. A similar appearance can be achieved when using plastic, but the glass looks more "representative", and also retains its original appearance for a very long time — thanks to scratch resistance. Such lamps turn out to be heavy, but this can be both a disadvantage and an advantage — a massive body is more stable and creates an additional sense of solidity. But the unequivocal disadvantages of glass lamps can be called fragility and high cost.
— Wood. Another material used in decorative lamps. It is worth noting that the tree not only looks good, but is also quite practical: the strength of such a material is comparable to the characteristics of plastic (and sometimes even higher), and small scratches on it can be completely invisible. However, wooden cases are more difficult to manufacture and much more expensive — so much so that the described advantages do not justify the difference in price. And in style, they fit poorly into the equipment of a modern workplace. Therefore, wood in table lamps is used exclusively as a design material.
— Ceramics. Ceramic gives the luminaire a cozy “homely” look, making it well suited for table lamps and decorative models (see “Type”). The main disadvantage of this material is the fragility and sensitivity to shock. Indeed, many types of ceramics are capable of cracking from a fall or other strong impact, but there are also high-strength varieties; specific properties of the material, usually, are directly related to the price category of the lamp.
— Textile. Textiles are practically not used in cabinets, but are often found in plafonds and lampshades, especially among table floor lamps (see "Type"): the fabric gently scatters the light passing through it and can give it one shade or another.
