Emission angle

The beam angle indicates the size of the area that the lamp can illuminate directly. The larger the beam angle, the wider the room is illuminated. If you want to set specific highlights, select a small emission angle. At 240°, our lamps are comparable to the light of a classic incandescent lamp, as they illuminate the room almost completely in the direction of the ceiling when used in a luminaire.


Candela is an indirect unit of the luminous intensity that arrives on a surface 1 metre from the lamp. Originally, the light of a normal household candle was defined with the value of 1 cd (cd is the abbreviation for candela). Today, this unit of luminous intensity is hardly used any more and one speaks of luminous flux (measured in lumens) or illuminance (measured in lux) to give a measurement of the brightness of lamps and their use. We currently manufacture our lamps with luminous fluxes of the standard 400 and 600 lumens, which are suitable for replacing conventional incandescent lamps with 40 or 60 watts.

CRI (Color Rendering Index)

The CRI is the measure of color rendering that a light source emits. The maximum value of the index is 100, which means no distortion of the colours by the light source. Our LED lamps offer a very good colour rendering value of >87, which is very close to pure colour rendering.


Dimming means that the light intensity can be seamlessly regulated. If your lamp has a built-in dimmer, you can use it to adjust the brightness of our dimmable LED lamp. With the incandescent lamps, you could choose the brightness almost arbitrarily, which is exactly how our intelligent dimmable products are designed to work. Our dimmable LED lamps can also be used without dimmer function of the luminaire. In the near future, however, we will also be offering products that are not dimmable. This reduces the purchase price, but you can no longer regulate the light intensity.


By definition, LED lamps are electronic devices that should not be disposed of in normal household waste. Dispensing into the specially prepared boxes ensures optimum recycling of the valuable materials of the lamp. In which stores and disposal companies you can best dispose of your lamps can be found here: http://www.lightcycle.de/verbraucher/sammelstellensuche.html.  See also Recycling.

Colour spectrum

The colour spectrum is the part of the electromagnetic spectrum that humans can perceive without technical aids. This refers to the classic rainbow colours in the range between 380nm and 750nm. Radiation with an even smaller wavelength is then UV radiation or X-ray radiation. Above that, one is dealing with the infrared range or with radio waves.

Colour temperature

The colour temperature is the measure of the perceived color impression of a light source and is measured in Kelvin (K). The colour temperature of lamps typically ranges between 2,700 Kelvin and 6,500 K. The incandescent lamp as well as our Carus lamps offer about 2,700 Kelvin, so-called warm white light with a homely atmosphere. Values of more than 3,300 Kelvin are referred to as neutral white light and above 5,000 Kelvin are referred to as daylight white or cold white. Cold white light is ideally used for working and has an activating effect.


LED lamps are still usually more expensive to purchase than other technologies. Taking into account the length of their service life, however, they are already the cheaper alternative to incandescent lamps and halogen lamps. Comparing the purchase, replacement and operating costs of LED lamps with incandescent bulbs, the LED lamps are by far the more economic option through their long service life and low power consumption. Our lamps are well manufactured and 100% tested before distribution, providing a product that saves you electricity and money.


A lamp is a light source. The lamp produces light by converting energy and is usually used as part of a luminaire. In colloquial language, the lamp is synonymous with the actual term luminaire. Here, however, we correctly separate lamp/bulb and luminaire.

Life span

LED lamps have an extremely long service life of up to 40,000 operating hours, which can be more than 40 years with a regular use of 2.5 hours per day. However, their light output decreases over time. The service life usually indicates the operating time during which the LED lamps provide more than 70% of their initial light output.


LED is an abbreviation for “light-emitting diode”. This is an electronic semiconductor device based on crystals. If current flows through this diode, electrons move from layer to layer of the crystals and emit photons. We perceive these photons in different wavelengths, depending on the nature of the semiconductor, or in short: we see light.


Luminaires are objects used for lighting and thus either have a fixed bulb or a socket for a bulb. There are ceiling lights, floor lamps, wall lights, table lamps and much more. In common parlance, luminaires are also referred to as lamps, but here we correctly distinguish between luminaires and lamps/ bulbs.  


A lens is an optically effective component with two refractive surfaces, at least one of which is convex or concave curved. With LED lamps, a lens has the function of focusing or diffusing light and thus defining the beam angle. The light from an LED emits direct and radiant light away from the light source without the need for a large amount of omnidirectional radiation.


Lumen (lat. light, luminaire) is the photometric unit of luminous flux in relation to human perception. Luminous flux is a measure of the total visible radiation emitted by a radiation source, i. e. the total quantity of light emitted by a lamp. Thanks to the EU regulation, lumen replaced the traditional unit watt of light bulbs, as it is not the current consumption that is the determining factor, but the light emitted by the lamp. As a general rule of thumb, it is often said that a conventional 40 watt lamp emits 400 lumens. This rule is not 100% appropriate, but a helpful orientation. Human eyes perceive blue light and red light as darker, green and yellow light as brighter. For this reason, different light colours also provide different lumen values under otherwise constant conditions. 


LED lamps have a very long service life and do not contain toxic mercury. However, since they contain electronic components, it is advisable to dispose of them at the end of their service life in the same way as electrical waste at the recycling centre. In addition, our lamps do not use adhesives and thus make recycling possible in an optimal way, as plastics and aluminium can be easily separated from the electronic components.

Switching capacity

LED lamps cannot be switched on and off indefinitely. The switching capacity of LED lamps is up to 600,000 switching cycles, which is more than 100 years under normal use. LED technology thus far surpasses energy-saving lamps and incandescent lamps by far.


The socket is the connection between the lamp and the energy source. Sockets are standardised, so that you can equip your luminaires with new matching lamps. For this purpose, your luminaires have a socket that accommodates the lamps. We currently supply the common sizes E27 and E14, the so-called screw threads. GU10 and GU 5.3 lamps are planned.

Starting time

The starting time is the duration from switching on a lamp to reaching its maximum brightness. LED lamps and halogen lamps are generally quite fast, so our lamps achieve full brightness in your room after just 0.2 seconds. This measure was particularly being discussed in the case of energy-saving lamps, with a starting time of sometimes more than 30 seconds.


Watt is a unit of power and is used as an orientation value for the luminosity of conventional incandescent lamps. However, since energy-saving and LED lamps require far less power to produce a certain brightness, the wattage rating loses its significance. Instead, the lumen value is used today. The rule of thumb is that a 40 watt lamp emits about 400 lumens.


Transformers are a part of retrofit lamps. Since the mains voltage conducts alternating currents and the LED lamps require a direct and also significantly lower current than the mains voltage, a transformer converts the current. We are currently working on solutions that do not require a transformer. 

Heat generation

In contrast to conventional lamps, LEDs convert electricity very efficiently into visible light. About 25% of the energy is turned into light. With the old incanscent bulb, only 4% is converted into light and the remainder is converted into heat, which is why the old bulb reaches such a high surface temperature in operation. Nevertheless, even with today’s LED lamps, part of the energy consumption still flows into unwanted heat. Since heat damages the LED chips, it is important to dissipate the heat from the LED chips. The so-called luminous efficacy (i. e. the ratio between the used electricity and the generated lumens) is improved by further development on a daily basis, so that heat dissipation becomes better and better.