Brightness
The standard brightness of the on-camera light (see "Type"). Usually, most of these models have the ability to adjust the brightness, so the maximum value is given in the specifications.
When shooting at a short distance, devices that are too bright can “overexpose” the scene, degrading the quality of the shooting (and it can be much more difficult to compensate for excessive brightness in post-processing than the lack of light). So when choosing for this indicator, it is worth proceeding from the specific conditions of use.
Number of diodes
The number of light-emitting diodes (LED) provided in the on-camera light system (see "Type").
The abundance of LEDs allows you to achieve good brightness at a relatively low cost of the entire device — there are many light sources themselves, but they are relatively cheap. However, these models can be inconvenient to carry on camera and work in tight spaces. In turn, compact lamps with a small number of LEDs are more convenient, portable and "manoeuvrable", however, they are either inferior to more "multiply charged" models in terms of brightness, or are noticeably more expensive.
Colour temperature
The colour temperature of the light emitted by the device. Most of the classic flashes have a standard colour temperature of 5500-5600 K, so this parameter is usually not given for such lamps. But on-camera light sources (see "Type") can differ markedly in this indicator, and we will talk about them.
Colour temperature characterizes the overall shade of the glow emitted by the device. At the same time, an interesting nuance is that low values \u200b\u200bcorrespond to colours that a person perceives as warm; and as the colour temperature rises, the hue shifts more and more towards cool colours. For example, for a 60 W incandescent lamp, the light of which has a pronounced yellowish colour, this parameter is approximately 2700 K, and for a fluorescent lamp that produces “daylight” light with a bluish tint, this parameter is about 7000 K.
In general, the colour temperature of lighting is one of the most important parameters when shooting: it determines the colour balance of the image "seen" by the camera. In camera settings, this indicator is called "white balance". It can also be determined automatically, however, for the most reliable colour reproduction, it is still desirable to set its values according to the known colour temperature of the lighting.
Specifically, in on-camera light sources, the colour temperature can be either constant or adjustable. In non-adjustable models, the value of this parameter is the same as in most flash units...— 5500 K, which corresponds approximately to neutral white. Adjustment also provides the possibility of at least lowering the colour temperature — usually up to 3200 K, which approximately corresponds to warm white light. In addition, occasionally there are models in which the maximum colour temperature exceeds 5500 K, reaching 6000 K and even more.
The ability to change the colour temperature can be useful not only for shooting as such, but also for “matching” the lamp with other light sources. The fact is that if several simultaneously used light sources have different colour temperatures, the colour rendition on the scene being shot will be unreliable — to the point that a monochromatic object illuminated by different lamps from different sides may look like a two-colour one. One way to avoid this is to set the colour temperature of the on-camera light to match the ambient light. However, it is worth noting here that the methods of adjusting the shades and the accuracy of such adjustment may be different. The most advanced option is to use two sets of LEDs, with a warm and cold shade of glow; By changing the brightness ratio between these sets, you can also change the overall colour temperature — and quite smoothly and accurately. Another way is to use coloured diffusers (see below), but here the adjustment is stepped, with fixed values (with and without a diffuser). In some devices, both of these methods are combined.
