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.
Power management
The ability to manually change the power of the light flux emitted by the flash (with a constant pulse duration, see above). This feature is present in most modern models; it allows you to set the optimal parameters for shooting, so as not to “overexpose” the frame.
The characteristics of models with power management usually indicate the levels to which it can be set. Traditionally, each next (in descending order) level corresponds to half the power than the previous one, and they are indicated by fractional numbers: 1/1 (full power), 1/2, 1/4, 1/8, etc. The features of flash power control depending on the shooting parameters are described in detail in special sources, however, anyway, the more setting levels, the more options you have for setting the optimal parameters. This is especially true for shooting at short distances, where the risk of excessive “flare” increases.
Illumination angle
The angle of illumination provided by the on-camera light source (see "Type").
A large illumination angle, on the one hand, allows you to simultaneously cover a larger area, which is especially important when shooting long shots (at short focal lengths). On the other hand, to achieve sufficient brightness, this requires a large power of light sources, which accordingly affects the price and power consumption of the device. A small coverage angle, in turn, gives a small spot size of the light, but it allows you to achieve good brightness at a relatively low power.
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.
Power source
The type of element used to power the flash.
— AA. Powered by replaceable cells of standard AA size, known in everyday life as "finger-type batteries". The main advantage of such a power supply is the ability to quickly replace “dead” batteries with fresh ones: the replacement process takes one or two minutes on the strength (whereas for the built-in battery, charging is often the only option, which takes a long time). AA elements are sold almost everywhere. On the other hand, with such a power supply, you will either have to regularly spend money on disposable batteries, or separately purchase AA batteries and a charger for them; anyway, additional costs cannot be avoided. Another drawback is the dependence of the battery life of the flash on the quality of the batteries: when using cheap cells that are not designed for serious “loads”, the number of pulses per charge can be significantly (several times) lower than stated in the specifications. However, these shortcomings are generally not critical, and this type of food has become quite widespread. Most modern flashes use
2xAA,
4xAA,
6xAA, depending on power.
— AAA. Powered by replaceable cells (batteries or accumulators) of standard AAA size, known under the informal name "little finger" or "mini finger". Such elements are completely similar to the above-described AA and differ only in smaller sizes, wh
...ich makes it possible to reduce the dimensions of the flashes themselves accordingly. However, for a number of reasons, they are used less frequently. Mostly 2xAAA are used.
— Battery. Powered by its own original battery, which is not related to standard sizes, and sometimes also non-removable.
On the one hand, in some aspects, such a power source is much more convenient than replaceable batteries. First, it initially comes in a kit, and the device is ready to work out of the box. Secondly, in the same kit there is usually a charger (or the flash itself connected to the network plays its role). Thus, when using it, you do not need to spend money on buying batteries — everything you need is already included in the kit. In addition, we note that special batteries are often more capacious, more powerful and at the same time more compact than replaceable cells; besides, they are easier to "fit" into the overall design of the flash and reduce the size (although the built-in batteries are different). On the other hand, such power has one key drawback: when the charge is exhausted, the battery will most likely have to be recharged, and this takes time and the availability of an outlet (or other external power source). In the best case, if the battery is removable, you can purchase a spare for it and keep it ready — but this feature is not available in all models.
In light of all this, the main field of application for batteries is "flashlights" for video — sources of on-camera light (see "Type"). It is in such devices that high capacity is of key importance: you have to shine "constantly and a lot", and with a high power of the light source, batteries cannot effectively cope with this task.
— CR123A. Replaceable cylindrical batteries, slightly thicker and noticeably shorter than AA batteries, have a diameter of 17 mm and a length of 34.5 mm. They also differ in operating voltage — 3 V. Some time ago they were quite popular in photographic equipment, but today they are extremely rare.
