How to make solar powered lighting? Artificial lighting in the house. How to compensate for the autumn sun deficit

Homeownership outside the city is not just a luxury home, but also land plot, requiring careful design in the process of arranging in the landscape style you like. At the same time, one should not forget about the illumination of the territory, without which it is impossible to walk around the garden at night.

In addition, it is also considered an ornament, thanks to which plants that become invisible at dusk acquire a fabulous and exclusive appeal when properly illuminated. However, which lighting method should be preferred? It is not always possible to supply electricity.

The way out of this situation lies in the arrangement of lamps on solar panels. They appeared in our country relatively recently, but quickly won a huge demand among the owners of country cottages.

The Secrets of Solar Lighting

What is the difference between conventional lighting? The design of devices includes certain details and can have a variety of parameters, external characteristics, while possessing similar principle functioning. It consists in the fact that the incoming energy from the photocell is transferred to the battery, and then to the LED.

The upper part of the device is covered by a ceiling, equipped on special legs, or suspended on a mount. Look at the photo of the arrangement of solar lighting devices on the resource.

The area of ​​use of these devices is diverse, not limited exclusively to private households. They originally fit into the landscape decoration of park areas, are used as lighting for the facade of buildings, successfully decorate fountains and sculptures.

Varieties

To the most modern models solar devices include lawn, park, and wall. The most common are wall-mounted options that illuminate garden areas and squares.

Such an element can be located in a place illuminated by the rays of the sun. The batteries in these instruments support lamp operation for ten hours.

Devices for public gardens are equipped with large aluminum panels. Their difference lies in design features capable of protecting the contents of the luminaire from moisture. Undeniable dignity there is a long operating period. Such garden lighting works smoothly even in bad weather.

Lawn appliances in most cases have small dimensions. They use LEDs as a luminous part. As for the form itself, the dignity of solar lighting fixtures lies in the diversity and style of each individual model. Lanterns are used to illuminate paths, plants, and the attic.

Advantages and disadvantages

The advantages of such devices include a diverse area of ​​​​use. They are well suited as interior decor for suburban residential buildings and office buildings. By equipping garden lighting on a battery that operates from sunlight, even in the shady part of the garden, it is possible to focus the necessary attention on an object placed in that area without any problems.

In addition, such lanterns will help shrubs and trees develop well, as they will be illuminated at night. Operates lighting from solar batteries and in the squares, on the streets.

At the same time, when planning such a purchase for a suburban area, it is important to understand that many models are not repaired. Also the most regular options Doesn't charge quickly, especially on cloudy days. In addition, not every battery tolerates cold very well. This moment important to consider when buying a particular model.

However, despite the presence of disadvantages in the characteristics of solar lamps, they are not without numerous advantages:

• mobility;
• security;
• variety of capacities;
• saving electricity;
• variety of sizes, shapes, shades.

What nuances to pay attention to Special attention at the time of buying

Since in these lamps the light source is LEDs, their required amount depends directly on the intensity of the lighting. Also an important nuance that requires utmost attention in the acquisition process is the type and characteristics of the battery. The duration of operation of the LEDs at dusk depends on the voltage, as well as the capacity of the device.

The level of protection of the device is indicated by special numbers, as well as letters. At the same time, the higher the marking number, the greater the protection of the device from negative impacts environment. However, there are lighting devices with a motion sensor that are equipped even on water. Their difference lies in the ease of installation in the required place.

In this case, it is desirable to use these devices as additional lighting. It looks quite effective in combination with spotlights.

Most requested options

Today, garden lighting devices are presented on the market as products of foreign and domestic manufacturers. Which company to choose depends solely on your preferences. If you need to learn how to make a solar device with your own hands, watch a video from professionals.

Among the goods from domestic manufacturers, pay special attention to Cosmos devices, which are equipped exclusively in areas with unhindered access to the sun's rays. It is in this embodiment that battery charging will be observed, and at night the energy will turn into amazing lighting.

Uniel lamps belong to foreign high-quality goods. Their main purpose is to provide high-quality illumination of the territory and decoration structures. Lanterns of this type are created in an exclusive design and can be used both as lighting devices and as an unusual decoration.

Photo of solar lamps

Almost every greenhouse grows exotic plants from tropical countries, where there is more sun and the day is longer. Without artificial lighting, many plants simply will not survive. Or they will survive, but is this life: do not bloom, do not grow as it should.

When the lighting is as close to natural as possible, the plants are happy. And it would be good to think about this at the stage of designing a winter garden.

Daylight

I have one drawback, - the user writes kidar. - Lack of money. Therefore, the implementation of many ideas is stretched for an unacceptably long period.

A hot, but not yet fully realized dream of a forum member is a greenhouse. By diploma, he is an electrical engineer, so it was easy for him to think over the lighting of the room. The whole architecture of his greenhouse is aimed at ensuring that the plants receive as much sunlight as possible.

Orientation to the south allows you to make the most of the light of the Sun.

Thanks to the arched design with calculated inclination, sunlight always falls perpendicular to most of the surface of the panel.

A transparent coating occupies half of the ceiling, and this provides illumination that even continuous glazing of the walls will not give.

White walls and light floors reflect light and enhance general level illumination.

Due to the non-ideal transparency of cellular polycarbonate, the light in the room is diffused.

Illuminate or illuminate?

Illumination - a luminous quantity equal to the ratio of the luminous flux incident on a small area of ​​\u200b\u200bthe surface to its area. That's what the encyclopedia says. AT in practical terms you can draw an analogy with a watering can: you need to understand how much water falls on a particular carrot in order to calculate how long to water the garden.

Illumination is inversely proportional to the square of the distance from the lamp to the surface. That is, if you moved a lamp that hung 25 centimeters above the plants, and now it hangs at a height of half a meter, then the illumination will decrease four times. The illumination also depends on the angle at which the lamp is located. It's like the sun - at its zenith in summer it illuminates the earth several times more than on a winter day, hanging low above the horizon. All this must be taken into account.

When planning your greenhouse lighting, think about how much light your plants are missing, whether you are going to light them up or fully light them up. If you only need to illuminate, then you can get by with cheap fluorescent lamps, almost without caring about their spectrum. But it is better to choose longer lamps - they are more powerful, and their light output is better.

And if there is no natural light, then you still have to think about the spectrum.

Blue and red

As we remember from school biology lessons, light in a plant is absorbed by various pigments, mainly chlorophyll, and this happens in the blue and red parts of the spectrum. And if you choose the right spectrum, alternate the duration of light and dark periods in the greenhouse, then you can speed up or slow down the development of the plant, shorten the growing season, etc. Therefore, for example, in greenhouses sodium lamps are used, in which most of the radiation falls on the red region of the spectrum. Pigments with an absorption peak in the blue region are responsible for plant growth and leaf development. Plants grown under a regular incandescent light bulb tend to be excessively tall: they lack blue and reach up to get some.

Incandescent lamps are the cheapest, but the worst source of light for plants, not only because of the lack of blue in the spectrum. Most of the electricity in them turns into heat, so these lamps are placed as far as possible from the flowers, and this further reduces their efficiency. They are used only for heating air and in combination with cold light fluorescent lamps, in the spectrum of which there is little red.

It turns out that the lamps in the greenhouse should contain both red and blue colors of the spectrum, and now many manufacturers offer this. fluorescent lamps. Phytolamps are more suitable for plants than conventional fluorescent lamps that are used in rooms.

“The maximum radiation in phytolamps falls on the red and blue parts of the spectrum because it is these parts that plants need for photosynthesis. And the "daylight" lamps are dominated by the white part of the spectrum, which is convenient for our eyes and "unnecessary" for plants, ”says the user ANTI killer.

For large winter gardens, discharge lamps are suitable. They are considered the brightest. One such compact lamp is capable of illuminating large area greenhouses.

But all specialized lamps are much more expensive than usual ones, and, according to our members of the forum, you can simply install a powerful lamp with a high color rendering index (the lamp marking starts at 9). In its spectrum will be all the necessary components. Bonus: it will give much more light than a special lamp.

Daylight hours

Is there a limit on the amount of light for plants? On and this question, of course, was discussed.

Dess:

The sun gives up to 100,000 lux, so it is almost impossible to achieve this with lamps. Most cheap option- fluorescent lamps. The disadvantage is that the light output is 1.5 times less.

Sodium lamps and LEDs have the same light output, but at the same power, the lamps are 8-10 times cheaper than LEDs, so LEDs are definitely losing so far. But in 3-5 years this may change - LEDs are getting cheaper.

Usually in greenhouses, lamps are installed above the plants about half a meter from top sheet. For light-loving plants, the height is reduced to 15 centimeters. Experienced flower growers do this: they placed the lamps higher, and then gradually brought the plants closer to them, setting them on various coasters. The higher the plant becomes, the smaller the stand, then it can be removed completely.

The lamp should be placed along the entire length of the rack with plants. If the lamps are of low power, then they are mounted in several pieces and equipped with reflectors. general power lamps on square meter area with plants should be 100-150 watts.

In the winter garden of a forum member Dima Danilov three types of lighting: light from windows, artificial lighting from fluorescent lamps under the ceiling and hanging phytolamps. On sunny days, the phytolamps do not turn on. Last year there was a very "gray" winter, so both additional illumination sources were used.

The forum member places phytolamps at a distance of 10-30 cm from tall plants and up to half a meter from low. There are no problems - the heating of the lamps is small. “In the winter garden, it would not have been possible without phytolamps, because. ordinary luminescent ones would not have saved, ”says Dima Danilov.

And here Sazanvld believes that “all phytolamps and sodium lamps are a complete scam honest people on their hard-earned money. He prefers metal halide lamps, in particular spotlights. Here are his arguments:

1) They have the highest efficiency, it is not for nothing that they are used to illuminate stadiums and buildings. Accordingly, they are also economical.

2) A spectrum ideal for plants. Advanced aquarists and growers aquarium plants for sale, use them.

3) Low price, while one lamp illuminates 3-4 square meters.

The main thing is not to confuse metal halide spotlights with conventional halogen ones (these are not suitable).

Mysterious and beautiful

At night time winter Garden it will look mysterious and beautiful if you place the lamps in its separate corners, preferably under the plants. Multi-colored lamps will achieve a magical, cosmic effect. It is good to illuminate the decorative elements of the greenhouse with lamps with reflectors that create a directed stream of light.

Ideal light sources for illuminating plants are based on semiconductor LEDs that emit throughout the visible range: from near infrared to ultraviolet. In addition, their service life is practically unlimited. Such lighting is used in space hydroponic greenhouses. But they are very expensive, so they are not particularly common.

Irregular additional lighting will not make any sense. Turning on the lights from time to time, you will only bring down the biorhythms of plants. For full development, plants, especially tropical ones, need a long daylight hours, 12-14 hours. Then they will bloom and feel good. Ideally, the backlight should be turned on a few hours before dawn and turned off a few hours after the sun has set below the horizon. In order not to adjust your regimen to capricious plants, you can use a dual-mode timer-relay.

Read about the most budgetary version of the greenhouse. And this video is about big house with a greenhouse - you may get some good ideas from it.

It has long been known that the daytime "sun in milk" (sky haze), high cirrus clouds or a bright spot instead of the sun behind solid loose clouds is the ideal lighting for shooting. Lights and shadows turn white, which means that both the best color reproduction and soft chiaroscuro can be obtained. As a rule, the illumination at this time decreases by half, and the light-sensitive matrix of the video camera gives the best resolution, because excessive illumination of the matrix leads to the spreading of electric charges of the photoelectric effect and, consequently, to a loss of image clarity.

For even illumination of multiple subjects and when shooting in large rooms it is better to use indirect (reflected) or strongly diffused light, and to avoid shadows from one person on another, you need to use several light sources.

Pay attention to the lighting: in living quarters it is almost always overhead, from the ceiling. This is not very good, too contrasting, in the cinema this light is called “prison”, because it is with such lighting that dramatic and tragic scenes. Try to use natural light from the window, and if the shooting takes place in the evening, turn on the floor lamp, table lamps and whatever else you can find to light up the scene more evenly.

A beautiful sky is best shot over bright reflective and shiny surfaces, such as sand, snow, water, otherwise the contrast will turn out to be excessive. Water at a high sun (more than 42 ° above the horizon) becomes dark, at a low one it sparkles, takes on the color of the sky.

Natural lighting of the scene (the sun) - best of all, if from the side - this way it will illuminate the shooting scene in relief. If the sun is behind you, then in the frame there will be a motley mess of cheerful shades. Fog is very good on outdoor shooting, it amazingly emphasizes the depth of the composition, the volume of the frame, therefore, on the set of a real movie, distant plans are often “blurred” with the help of special smokes.

In clear weather, the main sources of light are the sun and the sky. The spectral composition of direct sunlight depends on the position of our luminary relative to the horizon, since the atmosphere absorbs short-wave (blue-violet) rays more than red ones. As it rises above the horizon, the sun changes from red to white-yellow at its zenith, the color temperature rises from 2200°K to 5700°K. The color of the sky depends on many factors and varies from blue to blue, the color temperature correspondingly increases from 104 to 3 x 104 °K.

Shadows that are predominantly illuminated by blue skies appear colder than highlights (illuminated areas) under a yellow sun. Blue shadows and yellow highlights further increase the contrast of the image. During the day in cloudy weather and with the sun in a haze, the difference in the coloring of light and shadow is hardly noticeable (color temperature is about 5500 °K and 7000-8500 °K, respectively).

The sun at dawn or at sunset is above the horizon at an angle of 0-6 ° and gives a sharp contrast of chiaroscuro. Only the vertical surfaces of objects are illuminated, direct sunlight colors them red, shadows are black, other colors are muted. This position of the sun emphasizes the terrain and is suitable for shooting landscapes, a quiet surface of water in the opposite light. For close-up shots of people, such lighting is unsuitable, side light is especially unacceptable due to excessive contrast. Evening is a good time to shoot cityscapes, because even if there is enough light on the street, the windows of houses are already lit up.

The low sun (13-15° above the horizon) in the morning, evening or winter day gives a sharp difference in the illumination of horizontal and vertical surfaces. In the light, objects are painted in orange-yellow hues, and shadows - in blue (the color temperature of the sun is 2500-3500 °K, the sky is more than 15,000 °K). The contrast is high, the color reproduction is distorted.

The illuminated part of the face becomes golden warm shade. In close-ups, illumination with a built-in lamp is useful to equalize the illumination of the shadow part to the level of the brightness of the sky and correct its color. For long-range shots, morning lighting is more suitable than evening lighting, as the air becomes less transparent after a hot day. The low sun in cloudy weather does not give shadows and is hardly suitable for shooting.

Universal lighting happens when the sun shines at an angle of 30-60 °, the light is white, the color temperature is about 55,000 °K. At this time, the illumination of horizontal and vertical surfaces is approximately the same, and the color reproduction of the illuminated areas is the most successful. The shadows are blue and can be softened in the right places by reflective white screens on the stands. You can shoot both people and landscapes.

The sun at its zenith is not very suitable for shooting, since mainly horizontal surfaces are illuminated. But only such natural lighting happens in forest thickets, deep quarries, well-yards. It requires front lighting and back lighting, satisfactory results are obtained when shooting on light sand or snow.

On a sunny day, under the canopy of trees, a lot of light spots and glare are formed, because of which the contrast becomes prohibitive. For this reason, it is better to shoot in a park or in a forest on a cloudy day or with a hazy sun. It is advisable to choose a place for shooting in a clearing so that at least a small area of ​​​​the sky gets into the frame.

A ragged pre-stormy sky, when dark clouds break through bright sun, can be a great, but unpredictable lighting for the unfolding of dramatic events. Landscapes acquire internal tension. The sun behind a dense cloud in a blue sky gives a dim and diffused light, in which shadows disappear, objects become flat. Such lighting is not very good for shooting.

A cloudy day does not produce shadows, the contrast is very low, the color temperature is more than 6500 °K, the colors fade. The image is flat, additional means are needed to emphasize the volume and shape of objects. Lighting is suitable for shooting close-ups of people, but side directional lighting is desirable, especially for flat faces, color contrasts are needed. Bright warm backlight built-in illuminator will give the effect of shooting at the setting sun.

Illumination - basic concepts

illumination- this is a physical quantity that characterizes the illumination of the surface, created by the luminous flux incident on the surface.

The unit of illumination in the SI system is the lux (1 lux = 1 lumen per square meter), in the CGS - phot (one ph is equal to 10,000 lux).

Unlike illuminance, the expression of the amount of light reflected by a surface is called brightness.

illumination directly proportional to the light intensity of the light source. As it moves away from the illuminated surface, its illumination decreases inversely with the square of the distance.

When rays of light fall obliquely to the illuminated surface, the illumination decreases in proportion to the cosine of the angle of incidence of the rays.

For example:

• Sunlight at noon - 100,000 lux
• When filming in the studio - 10,000 lux
• Outdoors on an overcast day - 1000 lux
• In a bright room near the window - 100 lux
• On the desktop for fine work - 100-200 lux
• Required for reading - 30-50 lux
• On the cinema screen - 85–120 lux
• From the full moon - 0.2 lux
• From the night sky to a moonless night - 0.0003 lux

Lighting - basic concepts

As a rule, lighting is directional, diffused and combined.

• directional light- this is the light that gives the object pronounced highlights and shadows and in some cases glare.
• scattered light- this is light that evenly and equally illuminates all surfaces of the object, as a result of which there are no shadows, glare and reflections on them.
• Combined lighting is a combination of directional and diffused light.

Reducing the overall illumination changes the ratio between the brightness of highlights and shadows: the brightness of highlights decreases faster than shadows. This can be due to some illumination of the shadows with diffused light. Thus, a decrease in overall illumination simultaneously causes a decrease in contrast.

Lighting is simple if the light has one direction, and complex if it comes in several directions, from two or more sources.

Lighting will be hard when the light source is a voltaic arc or an electric lamp without fittings; softened - if it is obscured by a translucent screen (made of paper, milky glass, light fabric), and soft - when it is enclosed in a wide soffit with a translucent screen.

The type of lighting affects the shape of the shadows and the nature of the relief. With hard lighting, the shadow boundaries are very accurately defined, and the relief of the object is exaggerated - it seems that all the depressions have deepened. Soft lighting blurs the contours of shadows and reduces the relief of the object. Soft lighting further enhances this effect.

If the light source is close to the illuminated body, then the shadows will be cone-shaped and sharply defined. If two light sources send mutually intersecting beams into space, they will give a shadow and penumbra, which will soften the contrast of the image.

Rays falling on the surface of an object at an angle of more than 45 ° give direct illumination, and at a smaller angle - oblique.

Oblique lighting emphasizes the shape of objects and brings out their details well. Its variation is sliding illumination, when the angle of incidence on the surface of an object is close to zero degrees. Sliding lighting especially clearly reveals the texture of the object. To soften the contrast in gliding lighting, additional direct illumination of the subject is given, but from a weaker light source than the gliding light source.

When illuminated by artificial light sources big plans(portraits, still life, etc.) enjoy the following types lighting:

• Fill or general light- uniform, diffused, shadowless illumination of the object, having sufficient intensity for a short shutter speed. It is carried out by a combination of top and front light sources.
• key light- a beam of light directed at an object or its plot important part. Its task is to create the main lighting effect. Such light should give more illumination on the illuminated area of ​​the object compared to the illumination of the general light. Self-drawing light is rarely used, as it provides contrasting lighting, which makes it difficult to work out details in shadows or highlights due to the large range of brightness.
• modeling light- a narrow directional beam of light of low intensity, used to produce highlights that improve the transfer of the volume of an object and highlight shadows in order to soften them, and sometimes completely eliminate them. The purpose of modeling light is to improve the gradation of chiaroscuro. The device for modeling light is a deep narrow soffit with an ordinary incandescent lamp of low power or an ordinary soffit with a tube put on it.
• Contour, or backlight, light- back gliding light used to highlight the contour of the object from the background. Such light reveals the shape of the entire object or any part of it. The edge light source is placed behind the object at a close distance from it. A thin line of the light contour is obtained, which expands with the removal of the light source from the object. As a device for contour light, a soffit with an average reflector diameter is used.
• background light- light that illuminates the background against which the object is projected. The illumination of the background should be less than the illumination given by the general and key light. Background light is uniform and uneven. Usually it is distributed so that the light areas of the object are drawn on dark background, and dark ones on light. For uniform illumination of the background, light sources are used in a wide soffit, and to create light spots on it, in a narrow soffit. Excellent light softening results are obtained by reflected light, for this purpose umbrellas with a reflective surface and flat reflectors made of white fabric on a frame are used.

Any light source is a source of luminous flux, and the greater the luminous flux hits the surface of the illuminated object, the better this object can be seen. A physical quantity, numerically equal to the luminous flux incident on a unit area of ​​the illuminated surface, is called illumination.

Illumination is denoted by the symbol E, and its value is found by the formula E \u003d F / S, where F is the luminous flux, and S is the area of ​​the illuminated surface. In the SI system, illuminance is measured in Lux (Lx), and one Lux is the illumination at which the luminous flux falling on one square meter of the illuminated body is equal to one Lumen. That is, 1 Lux = 1 Lumen / 1 Sq.m.

For example, here are some typical illumination values:

Sunny day in middle latitudes - 100,000 Lx;

Cloudy day in middle latitudes - 1000 Lx;

A bright room illuminated by the rays of the sun - 100 Lx;

Artificial lighting on the street - up to 4 Lx;

Light at night full moon- 0.2 Lx;

The light of the starry sky on a dark moonless night - 0.0003 Lx.

Imagine that you are sitting in a dark room with a flashlight and trying to read a book. Reading requires an illumination of at least 30 lux. What will you do? First, you bring the flashlight closer to the book, so the illumination is related to the distance from the light source to the illuminated object. Secondly, you will place the flashlight at a right angle to the text, which means that the illumination also depends on the angle at which the given surface is illuminated. Thirdly, you can simply get a more powerful flashlight, since it is obvious that the illumination is greater, the higher the luminous intensity of the source.

Suppose the light flux hits a screen located at some distance from the light source. If we double this distance, then the illuminated part of the surface will increase in area by 4 times. Since E \u003d F / S, then the illumination will decrease by as much as 4 times. That is, illumination is inversely proportional to the square of the distance from a point light source to the illuminated object.

When a beam of light falls at a right angle to the surface, the luminous flux is distributed over the smallest area, but if the angle is increased, then the area will increase, respectively, the illumination will decrease.

As noted above, illumination is directly related to the intensity of light, and the greater the intensity of light, the greater the illumination. It has long been experimentally established that illumination is directly proportional to the intensity of the light source.

Of course, the illumination decreases if the light is obstructed by fog, smoke or dust particles, but if the illuminated surface is located at right angles to the source light, and the light propagates through clean, transparent air, then the illumination is determined directly by the formula E \u003d I / R2, where I is the intensity of the light, and R is the distance from the light source to the illuminated object.

In America and England, the unit of illuminance is Lumens per square foot, or Foot Candela, as the unit of illumination from a source with a luminous intensity of one candela and located one foot away from the illuminated surface.

Researchers have proven that through the retina of the human eye, light affects the processes occurring in the brain. For this reason, insufficient illumination causes drowsiness, depresses working capacity, and excessive illumination, on the contrary, excites, helps to turn on additional body resources, however, wearing them out if this happens unjustifiably.

In the process of daily operation of lighting installations, a decrease in illumination is possible, therefore, to compensate this shortcoming, even at the stage of designing lighting installations, a special safety factor is introduced. It takes into account the decrease in illumination during the operation of lighting devices due to pollution, the loss of reflective and transmissive properties of reflective, optical, and other elements of artificial lighting devices. Contamination of surfaces, failure of lamps, all these factors are taken into account.

For natural lighting, a coefficient for reducing the KEO (factor of natural light) is introduced, because over time, the translucent fillers of light openings can become dirty, and the reflective surfaces of the premises can become dirty.

The European standard defines lighting standards for different conditions, so for example, if the office does not need to consider small details, then 300 Lx is enough, if people work at a computer - 500 Lx is recommended, if drawings are made and read - 750 Lx.

Illumination is measured with a portable device - a luxmeter. Its principle of operation is similar to that of a photometer. Light hits , stimulating a current in the semiconductor, and the amount of current received is just proportional to the illumination. There are analog and digital light meters.

Often the measuring part is connected to the device with a flexible spiral wire so that measurements can be taken in the most inaccessible, while important places. A set of light filters is attached to the device in order to adjust the measurement limits taking into account the coefficients. According to GOST, the error of the device should be no more than 10%.

When measuring, observe the rule that the device must be placed horizontally. It is installed in turn at each necessary point, according to the scheme of GOST R 54944-2012. In GOST, among other things, security lighting, emergency lighting, evacuation lighting and semi-cylindrical illumination are taken into account, and the measurement method is also described there.

Measurements for artificial and natural are carried out separately, while it is important that a random shadow does not fall on the device. Based on the results obtained, using special formulas, a general assessment is made, and a decision is made whether something needs to be corrected, or whether the illumination of the room or territory is sufficient.

Andrey Povny

Shooting periods during the day are divided according to the height of the Sun above the horizon with a cloudless sky (Fig. 1) into low illumination in the morning and evening at a Sun height of up to (13 ... 15) ° above the horizon. The lighting color develops from red to white, in the shadows - from blue to blue. This period corresponds to the time of spectacular shots of sunrise and sunset. The ratio of illumination of horizontal and vertical surfaces changes sharply; more normal lighting at a height of the Sun (15 ... 60) °. The color of the lighting comes to white (average daylight), in the shadows the lighting is blue or blue. The illumination of the horizontal and vertical planes gradually equalizes and becomes the same at 45°. The contrast of lighting depends on the purity of the atmosphere and is softened by diffusers on the lighting fixtures. To eliminate the blue tint of shadows during color shooting, yellow-straw filters are installed on the equalizing light devices; anti-aircraft lighting, not very suitable for shooting due to the sheer-falling overhead light of the Sun. Increasing illumination of horizontal surfaces and decreasing vertical surfaces enhances the contrast of chiaroscuro. Shooting is carried out with the lower illumination of the object or a plot-important detail from lighting devices or reflector tablets: twilight (mode) lighting corresponding to the position of the Sun (0 ... 6) ° below the horizon and the sky without clouds. In this case, the brightness of the twilight sky, which creates illumination, varies depending on the purity of the atmosphere and the depth of the Sun's immersion below the horizon.

Rice. 1. Light periods of the shooting day

The necessary time for the dive is selected from the interval (15...30) min, during which the illumination should be such that the sky in the negative is worked out with density (D sky = D min + (0.1...0.9)). This practically difficult-to-determine time interval of the Sun's immersion gave the shooting the name regime (regime lighting). At this time, photography is usually carried out with the use of additional artificial lighting (backlight), the dose of which must change with the change in the brightness of the sky to obtain a constant ratio of natural and artificial illumination. In the south, the regime time is short, in the north it is relatively long (white nights). On fig. 2, a-h shows graphs of shooting lighting periods depending on the time of day and month for various geographical latitudes (cities). The graphs show the start and end times of the four main periods of natural shooting illumination for each hour of local time for various geographical latitudes from 35 to 70° every 5°. The curves are the locus of points for the solar altitudes -- 6°, 0°, +15° and -f 60°. highest height The sun for a given latitude on June 22 is indicated by a dot in the center of the graph and is provided with the corresponding number in degrees. These graphs correspond to direct sunlight in clear skies.

Rice. 2, a-h graphs shooting lighting periods depending on the time of day and month for different geographical latitudes (cities).

Illumination of horizontal and vertical surfaces of objects. Shooting objects can be different in different configurations. Their surfaces relative to light sources can be located horizontally, vertically or at an angle. A certain position of the main (drawing) light source - the Sun, as well as illumination from the sky create different illumination on objects, the difference between which determines the corresponding contrast of light and shade. The difference in illumination is a certain interval of the brightness of the object of the drug, which must be measured, matched with the characteristics of the film (processing) and reproduced in the negative (transparency).

The sun as a source of main light moves across the sky from the horizon upwards (standing height H) and in azimuth (from east to west), changing the illumination on all surfaces of the object in a complex way (Fig. 3, a, b). In most cases, scene shooting important elements the foreground of the object have vertically arranged surfaces. Facing the Sun, they perceive from it the main light, which is the key illumination for determining the shooting exposure. Depending on the height of the Sun, the key illumination changes and can be significantly lower than the illumination of horizontal, non-scene important surfaces. Lighting in cloudy weather has other characteristics.

At a low position of the Sun (Fig. 4, c), the vertical surface is illuminated by direct light almost along the normal N (angle α ≈ 0) and has maximum illumination with a low color temperature (2500...2800) K.

Rice. 3. Schemes of the movement of the Sun across the sky in terms of standing angle H (c) and azimuth (b)

Rice. Fig. 4. Schemes of illumination of the horizontal and vertical planes when the Sun is standing: low (o), medium (b) and zenith (c)

Horizontal surface perceives oblique, almost gliding light of the Sun and, according to the law of the cosine of the angle of incidence of light, has low illumination. The brightness of the vertical surface is high, the horizontal is low. At an average standing of the Sun (N - 45 °) (Fig. 4, b), the vertical and horizontal surfaces perceive the illumination from the Sun in the same way, the color temperature is close to the temperature of the average white light (5300 ° ... 5500 °) K, and the brightness of both surfaces are the same. At a high standing of the Sun (N - 50 ... 90 °) (Fig. 4, c), the vertical surface is illuminated by oblique rays of the Sun, and at the zenith by gliding rays and has low illumination with a color temperature of average white light of 5500 K. The horizontal surface perceives almost direct the sun's rays in high light and the same color temperature. The brightness of the vertical surface is low, the horizontal - high.

Fig.5. Illumination from the sky in the shadow from the Sun, where E c - illumination from the Sun, E n - from the sky

Illumination from the sky in the shadow from the Sun (Fig. 5) has a value of 6...8 times less than solar with relative uniformity. 98. Atmospheric features in daylight. The quality of daylight is determined by the degree of turbidity air environment located between the Sun and the camera. Atmospheric phenomena that affect the illumination, light pattern and color of an object include atmospheric, celestial and optical haze, haze, fog, drizzle and rain. If these phenomena occupy a small part of the area (10 ... 30%) within the photo frame, then they are elements of the shooting object with their own brightness and color and do not affect the lighting. If they serve as the environment in which the subject is located, then they largely affect the illumination and color of the lighting. Any atmospheric phenomenon and the conditions in which it develops affect the light-optical pattern and the photographic quality of the image, and the visual effects that occur, for example, in rain, snow or fog, specify the situation of the action. Atmospheric (molecular) haze is a uniform light veil (environment), covering the distances of the earth's surface. Caused by the scattering of sunlight by a layer of air. In clean air with relatively zero humidity, the rays of the blue-violet part of the spectrum scatter more strongly than the green, yellow and red ones, so the atmospheric haze, and with it dark distant objects, acquire a bluish color (“blue distances”). Atmospheric haze smooths out the differences in brightness and color of distant objects and thus worsens their visibility up to complete disappearance. The nature of the haze is determined by the color of the halo around the Sun and the state of the atmosphere. The presence of molecular haze makes the halo very weak, the sky around the Sun becomes bluish. With a relatively increased air humidity, the haze thickens, and the halo acquires a bluish-steel tint. AT black and white photography atmospheric haze is weakened by installing yellow, orange and red filters (especially in aerial photography). The use of these filters is not effective if the haze is caused by the scattering of light by particles of dust and fog, since in this case the scattering of sunlight in all parts of the spectrum is the same. In color photography, filters to eliminate molecular haze are not used. A small blue atmospheric haze near the horizon during color shooting is even undesirable, since the aerial perspective expressed by it destroys the dryness and rigidity of colors, chiaroscuro becomes softer, and the image takes on a certain color. Sky haze - a type of atmospheric haze, characterized by a high content of atmospheric moisture. The quality of solar illumination, which affects the illumination of the object and the color of the sun's rays, depends on the density of the celestial haze. The light of the Sun, passing through the sky haze in the blue-green part of the spectrum, is significantly weakened and becomes warmer. The white parts of the subject take on a slightly reddish tint, but the shadows do not have a pronounced blue tint as they are illuminated by whiter light. Sky haze has a positive effect on the quality of color in the image: the results are better than with pure blue skies and light molecular haze, aerial perspective is expressed more clearly. Significant impact on solar lighting renders a thick heavenly haze (professional expression "The sun in milk"). Lighting with it is similar to daylight, when the rays of the Sun pass through high cirrus clouds. At the same time, despite the fact that the illumination drops almost twice, the shadows are well illuminated by the diffused light of the Sun, the contrast of chiaroscuro decreases and the general illumination becomes the most favorable for creating a three-dimensional pattern. The colors of the object under such lighting are transmitted in the most full color, there are no color distortions from a clear blue sky. Optical haze is created by local air turbidity due to the temperature difference between the layers, which causes the appearance of air oscillating jets of air. Optical haze is especially noticeable in hot, dry weather over asphalt in the city, dry soil in the steppe, and heated roofs of buildings. Light in the presence of optical haze is sufficiently polarized, therefore, in this case, the use of polarizing filters is effective. Haze is cloudy air caused by solid particles of smoke, burning and dust suspended in it. The high intensity of haze reduces the visibility of objects sometimes up to 1 km. Over large cities in calm weather, there is haze associated with clogging the air with dust and smoke of local origin (smog). It makes the atmosphere near the earth's surface dark grey. The brownish or grayish-brown color of the haze significantly changes the color of the illuminated daylight: it makes it reddish, sometimes the Sun is perceived as red through the haze. Dust haze as a kind of haze in black and white shooting is not filtered by yellow, green and even orange filters. In any shooting, the sky is perceived as gray-white, and near the horizon as dark gray. The light scattered by the dusty haze is partially polarized, therefore, when shooting in the steppe regions, a polarizing filter is used to reduce the excessive brightness of the sky. Fog (a cloud lying on the ground) is an accumulation of small water droplets in the surface layer of the atmosphere with a height of up to hundreds of meters, reducing visibility from (1 ... 3) m to 1 km. Fog is formed as a result of sublimation or condensation of water vapor on aerosol (liquid or solid) air particles and is divided into evaporation fog and cooling fog. Evaporation fog occurs when additional water vapor enters cold air from a warmer evaporating surface, cooling fog occurs when the air is cooled below the dew point temperature. At the same time, the water vapor contained in the air reaches saturation and partially condenses. Cooling fogs are the most common. White light is strongly scattered by fog due to the significant excess of the diameter of moisture particles of the wavelengths of the spectrum rays. Only infrared rays with a wavelength greater than the diameter of the fog droplets pass well through the fog. When light reflected from objects passes through the fog, some of the rays reach the lens of the camera, while the other is scattered, and many weakened rays coming from the entire mass of fog reach the lens. The rays that have reached the lens draw an image of the object, and the scattered ones impose a uniform gray veil on it, reducing the contrast of the image. With a high density of fog, its veiling effect is significant, the pattern of the image is not observed, the photographic material in the camera is evenly illuminated by diffused light. Fog has its own brightness, in most cases more than the brightness of the object, since the “light source” in this case is itself. In fog, horizontal and vertical surfaces have the same illumination. First of all, blue rays are scattered in the fog, and lastly, red rays of the spectrum, therefore, a colored object, depending on the density of the fog, first loses blue, then green, and last saturated red tones. For this reason, a person's face, shot in fog, does not lose its pinkish hues. Bright red colors, fire and sources of red in the fog are clearly visible. As the distance from the camera to the object increases, the color of the object in the fog is quickly lost. At certain distances, the image of the object takes on pastel tones, as the fog greatly whitens the color, superimposing an additional white veil on each color tone, softening the contours and reliefs. When shooting against the Sun (kotrazhur), when its translucence is felt, the fog turns red, and the background appears as if through a reddish veil. When photographed from the Sun (to the north), the fog appears colorless, gray or bluish depending on its density. Drizzle - atmospheric precipitation in the form of very small drops with a diameter of up to 0.5 mm (larger than fog drops and smaller than rain drops). Drizzle falls from stratus and stratocumulus clouds and, depending on the density, has the properties of fog or rain. Rain - precipitation falling from clouds in the form of water droplets with a diameter of 0.5 to 6 ... 7 mm. The optical effect of rain lies in the fact that an additional optical medium appears between the camera and the subject in the form of a dense water sheet that absorbs and scatters light. When it rains, the drops themselves become a luminous medium that exposes the film (like fog, for example), so distant black or colored objects cannot be depicted as either pure black or saturated color. The color is whitened by the veiling action of rain as well as by mist. In dense continuous rain, first of all, blue colors cease to be distinguished, then green, and then red colors. In addition to this, in the rain there is a shine on all surfaces without exception, since the veil of rainwater makes them glossy, and the reliefs of glossy surfaces stand out well. Reflex light appears on the folds, bends and uneven surfaces, allowing you to clearly see the shape and volume of objects. Puddles of water on the ground, asphalt, pavement reflect the light of the sky, creating additional illumination from a lower point, in the presence of which it is sometimes possible to exclude the lower illumination of the plot important details object. Glare and reflections allow you to shoot against the lightest part of the sky (a kind of backlight) and get an image at relatively minimal illumination. When shooting in black and white in the rain, you can get multifaceted images (especially in a landscape), and when shooting in color, for example, a picture in which the color in the foreground of the image is relatively saturated, and in the depth of perspective is reproduced in the achromatic range of blacks and gray tones(red traffic light in the foreground with gray tone distant plans). Reflections and glare at the same time convey a sense of volumetric form and airy (tonal) perspective. Cloudiness, depending on the nature of the clouds and the degree of their distribution over the sky, creates different illumination in color daylight. There is a sharp difference in the intensity, contrast and spectral composition of illumination under the Sun with a cloudless sky and under continuous clouds with a closed Sun. The area of ​​clouds in relation to the sky-arch affects the share of scattered, reflected and direct light of the Sun in total daylight. The greatest illumination is observed when the sky is almost completely covered with thin light clouds with an open or slightly veiled Sun, the smallest - when the sky is covered with clouds (cloudy weather). The greatest contrast of daylight is observed when the Sun is open and the sky is clear, since the illumination from the sky is 6...8 times less than the illumination from the Sun (significant contrast). Less contrast - with a sky partially covered with white clouds that reflect sunlight well, and minimal or no contrast - with a sky completely covered with clouds. Data on illumination and color of daylight are given in the reference book.