Light and color: this is the secret to good photography

A photograph is made of light and color . These are the only two ingredients. Knowing how to dose them in a wise way allows you to go from an ugly or normal photograph to a fantastic image.

Understanding light is therefore necessary for a photographer to best express his idea and move from a simple representation of reality to something creative.

Understanding light doesn't require a degree in physics, but a little scientific knowledge will allow you to express yourself better.

The light

Light has incredible properties: it carries energy, under certain conditions it behaves like a particle, under others like a wave. More properly, the term light refers to the portion of the electromagnetic spectrum that is perceptible to the human eye (which is a small part of the spectrum).

The different wavelengths are interpreted as colors, from red (with longer wavelengths) to violet (with shorter wavelengths). Some cameras are also designed to see a greater spectrum, for example in the case of infrared photography. From a photographic point of view, the properties of light (which we have already dealt with in this article ) that interest us are:

• amount of light hitting our subject;
• quality of light , which can be diffused (with soft or non-existent shadows) or hard (in which there is a clear and decisive cut between illuminated areas and dark areas);
• color of light , which can be varied by placing colored filters between the light source and the subject;
• direction of origin of the light. Light only travels in straight lines, but can be redirected using a reflector. In this case the light can also be "coloured", using a non-neutral colored reflector (for example gold). Furthermore, unwanted reflected light must also be taken into account, for example from a colored wall placed near the subject.

Photography, light and colors

We know that without light there is no photography . General photography works in the visible light spectrum. We use the Kelvin temperature scale to describe the color of light. For example, a candle flame is 1,200 K , which is towards the orange-red end of the scale, and a cloudless day is 10,000 K , which is towards the blue end.

White balance

The human brain is good at correcting colors. For this reason, even when illuminated by a colored light, we know that the central band of the Italian flag is white. Unfortunately, that's not the case with cameras. Their "brain", though powerful, cannot perform such a simple task.

For this reason there is the white balance : we can tell the camera that has recorded an image using the available light (solar, neon, tungsten, ...) what it should consider white and then use it as a reference for the other colours.

With the white balance we therefore go to correct the colors recorded by our camera.

For this reason it is important to photograph in RAW format as it is possible to make this correction without loss of information. But be careful when doing a color correction. In some cases a "wrong" color that creates an atmosphere is better than a correct color that however leads to losing the meaning of the image.

For example, a subject lit by a candle has a warm, atmospheric tone that would probably be lost by over-white balancing.

RGB

Cameras can represent all colors, but in reality the photo sensor is designed to record only the three primary colors: red (Red), green (Green) and blue (Blue).

All other colors are obtained by adding these three primary colors: yellow=green + red, cyan=green + blue, magenta=red + blue, and so on up to the color white=red + green + blue.

Since different colors are formed by the addition of other colors, RGB colorimetry can be defined as additive (note: black is formed by the total absence of these colors).

Each color has a variation range of 255 “steps”, so we can identify pure red as 255, 0, 0, white as 255, 255, 255 and black as 0, 0, 0. In this way yellow pure can be identified as 255, 255, 0 and a deep purple as 113, 58, 210.

cmyk

The RGB model works great on cameras and monitors where we add light to black to create color. When we print, however, we're starting with a white piece of paper and subtracting from that white to create color.

Instead of red, green, and blue as primary colors, printers use cyan , magenta , yellow , and black (CMYK) to create all other colors. “K” is used for black because it is the last letter of the word (blacK) and is not used by any other color.

To save ink costs and to produce deeper black tones, dark, unsaturated colors are produced by adding black ink rather than just the combination of cyan, magenta, and yellow.

So while in the RGB model, pure red is defined as 255, 0, 0, the exact same color in the ink-printing world of CMYK is something like 0, 100, 100, 0.

How photographers control light

As photographers, we have to manipulate light to make our image. If we work in the studio, it's quite simple since we have all the equipment to do it: light sources whose intensity, color and direction we control, reflectors to illuminate the parts in shadow and therefore soften them more or less decidedly, screens more or less translucent to diffuse light or create shadows exactly where we want them.

When we are outdoors, we have less control, especially in landscape photography. In this case we just have to resort to nature: more or less cloudy skies and shooting in the golden hour are certainly the simplest tricks to use (in this article you will find other tips for taking portraits with natural light).

Conclusion

Learning how light works is essential for a photographer. Understand how direct light or diffused light, time of day and season, direction and angle of incidence, factors such as screens and artificial or natural diffusers (mists, fumes, rain, …) are all elements that influence the way the camera perceives light is crucial for a photographer. Learning to see light is the secret to amazing photographs.