Holistic Photography: Light is a medium for communication. Light is energy. Light is life. Who can understand it? Light is essential for our art, so we’ll venture deeper that most people so as to know and appreciate the nature of light.
We can see light in the visible spectrum; the rainbow’s arc spreads the constituent colours before us against the backdrop of the sky. White light is of our mind’s creation and as such, is subject to interpretation.
The sun radiates energy that allows us to live and thrive. That energy reaches us as light. About 1% of this light is invisible to us, but still affects us. Infra-red radiation warms us; ultra-violet causes our skin to activate healthy Vitamin D.
Direct sunlight is very bright. About an hour after sunrise and an hour before sunset we can set our camera’s exposure settings to some standard values and generally get a well-exposed photograph for subjects lit by direct light. You can try a shutter speed of 1/250th of a second, an aperture of f8 and an ISO of 100.
The sun’s brightness is diminished by obstructions, which might be dust in the atmosphere or clouds. These obstructions change the quality of the light in ways we can learn to anticipate so as to improve our ability to see.
Light can also be REFLECTED. Generally, it is enough to simplify light to being DIRECT from the original light source such as the sun, DIFFUSED such as the light that passes through cloud cover, and REFLECTED, when it bounces off something like the white sand on the beach.
Small light sources cast hard shadows. The sun is very large; but small relative to us, which is what counts. The high midday sun creates dark, sharp shadows. This is high contrast HARD LIGHT.
Suppose we have two different suns. The light from the second sun will lighten the shadow cast by the first sun; and vice versa. Here is the fundamental principle behind shadowless light.
Imagine the sun is behind a large layer of white cloud. The sunlight passes through the cloud and is diffused. The cloud now becomes the main light source. Our subject is lit from many different angles at once, so any shadows cast by one side of the cloud are lightened by the other side.
The illuminated cloud is a large light source and creates fewer or even no visible shadows. This is called SOFT LIGHT. The larger the light source relative to your subject, the softer the light. If the light is closer, it’s softer.
You can instantly change your photography by taking advantage of this knowledge. Instead of using the direct sun as your main light source, which will create harsh shadows, think about using a softer light source. This may be an overcast day, but these aren’t available on demand.
Instead, find a large white or cream coloured wall that’s facing the sun. By standing with your back to that wall, it will essentially act like a large soft light source. The difference it will make to your photographs is striking.
Light also has a colour. White light doesn’t exist; it is a combination of other colours. Our eyes will adjust for different colours of light to ‘see’ the real colour of things. But the original content of the light matters a lot more than most people think.
Mainly, we will be dealing with warm and cool colours. Warm colours are oranges, reds and yellows. They suggest firelight and comfort. Cool colours are shades of blue (and green). They remind us of ice and clean spaces.
We can talk about the colour of the light by using its colour temperature, measured in Kelvin. 2500K is a low colour temperature, characterised by orange candlelit; 10000K is a high colour temperature; a cool blue light. 5200K is normal for daylight.
We say that an object is white because it equally reflects all of the different colours of light that fall upon it. But a white tablecloth inside a candlelit restaurant is objectively a warmer colour; because only yellow, orange and red shades of light are available to be reflected from it.
A film camera, optimised for daylight’s full complement of colours, will show us the yellow colours that actually predominate in scenes lit by incandescent tungsten lighting as we normally find inside. We see more subjectively; what should be white appears to be white, and what should be blue appears to be blue.
A digital camera meets us half-way. We can take control of our WHITE BALANCE to tell the camera what should be white or neutral gray. This will correct our other colours simultaneously, which often makes a dramatic difference to our photographs.
A blue Bentley in a tunnel lit by sodium lights will appear darker to us than the same car lit by the Italian midday sun. Certainly this makes sense; there is more light outside. But let’s not stop there. Notice that the tunnel’s lighting is almost entirely yellow; there is hardly any blue light available to be reflected, so the blue car appears to be a darker shade.
It follows then that a yellow Bentley would seem to be a lighter shade under sodium tunnel-lighting than in the bright sunlight; and this is indeed the case. The yellow car seen under yellow light will seem almost white.
This matters, because the colour content of your light affects how your scene will look, even if you adjust your camera’s white balance. People look better under a warmer coloured light because any blemishes will appear lighter and therefore blend in better. Neon lighting is a cooler colour, so emphasises blemishes.
This is also why clothes bought in a store appear a different colour outside. In some stores that use halogen or neon strip lighting, the clothes may seem particularly off-coloured. Start to notice this effect if you’ve not already done so.
Un-natural light sources only approximate natural light. They take advantage of our visual system, which will see the same white light regardless of its actual colour content. Artificial bulbs that have only spikes of red, green and blue light will seem as white as daylight to most people.
Because large amounts of the other colours are missing from many modern artificial light sources, skin tones may not appear at their best, cars’ colours may be distorted and the scene will generally look a little odd.
The sun’s light can also reach us as different colours. The most obvious place to start looking at this would be with the answer to that age-old question, ‘Why is the sky blue?’.
We will say that light travels in straight lines. If an opaque object is placed in its path, a shadow (an reduction or absence of light) will be cast behind it. So how are we able to see without artificial lighting in shaded streets?
The sun’s rays hit the dust in the atmosphere and are scattered (called Rayleigh scattering). Blue light is about six times more likely to scatter, and spreads in all directions. We are therefore lit by a blue light from above by the sky.
Curiously, an astronaut on the moon was pictured kicking up the lunar dust around his feet. Without atmosphere, the moon’s sky appears black. But the astronaut had created a sort of mini-atmosphere around his feet. The dust refracted the sunlight and created a blue cloud of light by his boots.
Be aware that in the shade when the dominant light source is the blue sky that your scene is being lit by a large, soft blue light from above. Changing the white balance to the shade preset on the camera will restore natural colour.
But what about when the sun is lower in the sky? It reaches us at a more oblique angle than at midday, so it passes through more atmosphere; so more light has been lost to refraction by the time it reaches us.
At sunrise or sunset, almost all of the blue light has been scattered so we are left with the orange, red and even pink lights that paint the golden hours. People generally look better lit by the light at sunrise or sunset, especially if you set your white balance to compensate for the warmer colour temperature. And yes, red cars will seem more vibrant at sunset; have a look.
Apparently Turner’s landscape paintings were inspired by a volcano’s enormous eruption. He didn’t paint the lava flows; he was enthralled with the effect that the volcanic dust had upon the light. With more scattering in the atmosphere, sunsets were far more colourful and expansive. Large forest fires can create a similar, albeit smaller effect.
Why do we see an object as a specific colour? It is because it favourably reflects that colour and absorbs the other colours. Therefore, a large red building will actually reflect red light into a scene; it is well to take this into account when planning your photograph.
This is one of the building blocks for learning to see. Imagine the world as a vast palace of light, reflecting many times and taking up a vivid array of colours. You’re photographing the light; not the objects in the scene.
Where then is your primary light source? It may not be the sun. What is your secondary light source? Which other light sources will affect how your subject appears?
We can think about the direction of this light. If it is coming from behind us, it is on the front of our subject; FRONTAL LIGHTING, also called axis lighting. If it’s coming from the side of our subject, then it’s SIDE LIGHTING. And if it’s coming from behind our subject, then it’s BACK LIGHTING, also called contra-jour.
It will also be coming mainly from above or below our subject. Generally, lighting from above looks more natural, but be aware of the shadows that can be created by lighting that is directly above your subject.
Frontal lighting is simple to use if you’re careful not to include your own shadow in the photograph. It generally gives strong colours, but can look low-contrast and flat.
Side lighting rakes across the subject creating small micro-shadows; these create texture in our photographs. It can be more moody and evocative, modelling subjects well so they look three-dimensional. Shadows are on the opposite side of the subject to the light source and point towards it.
Back lighting is more difficult to use because your main light source for your side of your subject will probably be reflected light from nearby objects. It’s less predictable, higher in contrast, and can look amazing.
It will illuminate translucent objects such as foliage and smoke, making them glow. Back lighting is characterised by a rim light around your subjects; their being lit on the other side, so you can see where the edges are lit. This makes hair shine like a halo.
What happens when the light hits an object? There are two types of reflection to consider; SPECULAR REFLECTIONS off a shiny surface such as glass or a calm lake, and DIFFUSE REFLECTIONS off a rougher surface like cotton or brickwork.
Specular reflections are a lot more directional. The oft-quoted rule is that the ‘angle of reflection is equal to the angle of incidence’. Think of light’s reflections like playing the old computer game, Pong. If light hits an object at a steep angle, it will bounce off at the same steep angle on the other side.
In practice, this means that there’s a specific line of sight at which a light source or subject will be reflected in a shiny object. Imagine that an object has a mirror-shine; where would the main light source be reflected?
Smooth, shiny objects give more specular reflections so they seem glossier. Rougher surfaced objects that diffuse reflections scatter the light in many directions so they seem more matte. Objects generally have a balance of both; try and see whether diffused or specular reflections dominate.
After direction is considered, it is worth paying attention to how light’s intensity diminishes with distance. Again, there’s a neat rule, the Inverse Square Law, that states that ‘light intensity falls off as a square of the distance from its source’.
In English, this means that light is dramatically brighter the closer your subject is to it. In this way, a single candle is adequate light for objects within a few centimeters from it. Very useful; get your subject’s closer to the light source if you need more brightness.
Imagine that light is emitted from a small bulb. By the time it’s got as far as the radius of a ping pong ball, it’s still very concentrated. But by the time it’s as far as the radius of a yoga ball, it’s spread out over a far larger area; the surface of the ball.
This analogy explains why light intensity diminishes exponentially with distance; though the intensity of larger, softer light sources diminishes more gradually.
This effect is very noticeable with shaded window light. If your subject is close to the window, they’ll be lit by a much brighter light than an object deep into the room.
Direct sunlight is a different beast. The intensity of the light on Mount Kailash would be similar to the light in the Dead Sea. The several thousand metres of altitude may seem like a lot to us; but is nothing compared to the distances that the sunlight has already travelled.
Therefore, the inverse square law doesn’t affect sunlight. It will affect sunlight reflected off other objects as they’ll become light sources in their own right.
Holistic Photography is about learning to see, so the observation of light is of paramount importance. Use the principles here to inform and deepen your own understanding of light not in theory, but practically in the world around you.
What light sources do you see?
What colours do they contain, and which colour is dominant?
Where are they in relation to your subject?
Are they hard or soft?
Which types of reflections characterise your subject and the objects in your scene?
Light is energy, light is life; to see it clearly is a beautiful gift.