There are a lot of other interesting speakers scheduled for the conference, see the full list here – http://www.showlight.org/learn/ -

And if you’re around, don’t miss us in the wonderful Cesky Krumlov. It is impossible to express how excited we are to have our little venture be a part of a global conference such as Showlight. 

Sunlight
The Sun is a very intense and small light source very far away. All the rays from the Sun reach the Earth’s surface at the same angle, causing directional shadows. Sometimes the Sun’s rays are filtered in clouds and atmosphere, making the whole sky a large, glowing light source that gives out diffuse light. In this case the light rays hit Earth under many different angles. Under direct sunlight, shadows are very clear and dark, whereas on a cloudy day with diffuse lighting there might not be one single shadow noticeable. Usually, the daylight is a combination of these two – direct and diffuse. As clouds move and the weather constantly changes, sunlight never remains in a static state for long.

The pink backlight comes directly from the setting sun that is visible in the background. The blue hue in the shadows is diffuse light reflected from the clear blue sky.

All light is a combination of different wavelengths that make up the spectrum of light. Blue light has a shorter wavelength than green, and red light has the longest wavelength of the visible spectrum. There are even shorter and longer waves in the spectrum that we do not see, for example ultraviolet and x-rays, but our vision catches the approximate range of 390-700 nm. of the spectrum (from purple to red).White sunlight is a mix of the whole spectrum – all the different coloured light waves from blue to green to red.
In order to see objects of a certain colour under the light, the colour of the object needs to be present in the light as well: you are not able to tell the colour of a red object under completely green light. As the sunlight has a nicely even spectrum of all the possible wavelengths distinguishable to our eyes, we think that it is a very good light source as it does not exclude or distort any colours. The scientists call this capability good colour rendering.

Very often streetlights have limited capability to show colours. In this picture, the house is grey, the snow is white and the dog is brown. Under the streetlight, they however all seem yellow.

Open flame
By now, we have come up with several different ways to light our surroundings during the time the sun is not up. For a long time, fire was the main alternative to daylight. Bonfires and torches lit the nights for centuries as we learned to tame the fire and make use of it as a light source.
The light source of an open flame is usually positioned low – a bonfire on the ground or a torch on the wall; and is of a much lesser intensity than sunlight. Like sunlight, the spectrum of a candle flame also consists of all the visible colours. The exact colour of a flame depends on the burning material and conditions of the environment. Burning logs in a fireplace usually gives an orange radiation that we connect to homely warmth in our minds. Just like sunlight, light from open fire goes through continuous changes as well. As the flame flickers, the shadows of surrounding objects slightly move and create a lively atmosphere.

The diffuse sunlight reflected from the sky seems extremely blue when compared to the yellow of the lantern that tries to mimic the warm flame of an old gas lamp.

Artificial light
With the advances of technology, we have learned how to produce light in a number of different ways. From incandescent bulbs to fluorescent lighting, and to the revolutionary LED technologies of the modern times. All these different light sources have different qualities, however, a common feature is their active development towards resembling natural light. We want to be able to distinguish as many colours as possible, and with as little distortion as possible. Light sources based on heat radiation (such as the incandescent bulb) have a very broad spectrum by default, whereas technologies involving chemical reactions in the light creation (fluorescent, LED), have had to go through hard work to achieve the lighting quality.

Wouldn’t it be great if this light came from a lamp you could just switch on whenever?

Daylighting for the office
During the daytime when bright white sunlight pours in our windows, we want to balance the rooms further away with similar lighting. During working hours, we prefer lighting that gives out strong, white light that keeps us alert and feeling daytime-like. Lighting products labeled as „cool white“ try to resemble the intensity and colour of sunlight, turning our work environments to an ever-lasting daytime of activity. As mentioned before, natural light is never static, so advanced offices also have lighting sensors that regulate indoor lighting to match the intensity of the changing sunlight outside over the time of day. Good lighting design also disapproves static and even lighting levels throughout a building – this kind of lighting does not read as natural to our eyes.

The daylit cafe has an energetic feeling to it.

Candle lighting for the home
The incandescent bulb is the pioneer of electrical lighting. What we commonly refer to as „the“ light bulb, gives out an even, orange radiation that resembles light from a candle flame. Because we connect this colour to the warmth of a hearth, incandescent lighting has been a favourite for home lighting ever since its invention. Also the modern fluorescent and LED technologies copy this kind of light in their products labeled as „warm white“. Because we are used to bonfires on the ground and candles on the table, we like the aesthetics of lamps on the walls, floor and tabletops. We will find a single ceiling bulb harsh and unpleasant to our eyes. To mimic the diffuse / direct quality of natural light, we also use lampshades and reflectors, making the light more lively and interesting.

The fireplace is a symbol of everything cozy and homely. 

Shadows

A shadow is an area blocked from the light, usually behind an object. There is rarely such a thing as a complete shadow. In a natural environment, light bounces around and reflects from surfaces. Therefore even the shadow areas receive a certain amount of light.

The surfaces directly facing the light source are the brightest, transforming smoothly into a shadow over curves or sharply over angles. In case of texture, the coarseness of the surface will be visible because of the shadows from the reliefs. Even a highly textured surface will appear flat, if lit perpendicularly to the texture.

Depending on the light source, the shadows can be sharp or diffuse. A small or distant light source such as the Sun or a spotlight cause crisp, sharp shadows. A large light source nearby such as a window or a shaded lamp cause more diffuse shadowing. On a cloudy day when the whole sky functions as a light source, the shadows are extremely diffuse and clearly visible only in secluded crooks that are hard for the light to access.

There is a false theory about shadows being the opposite colour of the light source – this is not true. If there is no light, the shadows are black. However, our eyes do like to see an optical illusion of toned shadows in the opposite colour of the light. This is a similar phenomena to the afterimage we see on our retina after staring at a coloured object for long enough – close your eyes and you will see an image with inverted colours before your eyes. When looking at a strongly coloured light, the shadows will seem the opposite colour as our eyes grow tired of the main hue. Painters often use coloured shadows to underline this illusion that we receive through our eyes.

The actual reason for coloured shadows is the reflected light from the surrounding surfaces. As light bounces off an object, the colours not present in that object will absorb into the surface. For example a red wall will absorb all other colours, and reflect red light only. A good example of this are the distinct blue shadows on a sunny day outdoors – the colour comes from the light bounced from the blue sky. Paying attention to the colour of nearby surfaces and thinking about the travel path of light will help you determine the colour of shadow areas and make the picture more realistic.

The picture has been cut diagonally – the lower part of the photo is taken without the red toy – notice how it reflects red colour on the back of the white box.

Reflections

Reflections give us an understanding of the space around our subject frame. They help to determine the direction of light and can reveal the number and positioning of the light sources.

Reflections are more visible under a steep angle. We will see bright, sharp reflections on the curved edges of a round vase, never facing us directly. When looking over a calm pond, the water is more reflective further away, never directly at our feet.

There are two kinds of reflections – diffuse and direct. Most materials usually display a mix of these at the same time.

Direct reflections are specular highlights, direct images of the light sources in the space. They brightest ones have the shape and size of the light source. The smoother the surface, the clearer is the direct reflection it creates. The ultimate example is a mirror, able to reflect not only the light sources, but also all other objects. Another good example of direct reflection is the highlights in the eyes of portraits. On rough and textured surfaces, the direct reflection becomes blurred, but it should be remembered that it still represents the size and shape of the light sources and objects around them.

Diffuse reflection is present on all objects: all surfaces reflect light to some extent. This is what makes them visible for us. The light needs to reach our eye directly from the surface of the object. When light hits a surface and reflects back, the direction of reflection is more or less random, diffusing the light and breaking up the image. This is why the object is seen from all directions. It also appears to have a solid surface: all light received from the environment is mixed into an even blend.

Have a look at different materials of these objects and how they reflect the light. Notice how the table is very reflective as well. The only light source here is a window on the right. 

Refraction

When light passes through transparent materials,  it usually bends. This is an important issue with glass and water (and especially glasses full of water). The bending direction depends on the lighting angle – it always adjusts to be more perpendicular to the surface.

Article endlessly under construction according to your lovely feedback and questions, keep them coming!

Student works:

This is already the second year when Dare to Light is enlightening the 3D students of Tartu Art School. Thank you for having us back! We are discussing several other courses with this amazing little school – for example some advanced workshops with teachers of drawing/painting classes (this would be super exciting!)

Pictures from the workshop: