Perceiving Images - LIGHT
| Photographic Technique
Essentially, to photograph is to illustrate with light. Therefore, understanding the basics about light (in photographic technique), such as the best time, its color temperature, etc. is crucial to making a good photo.
Understanding how light operates in digital equipment helps us understand how colors are drawn and changed while photographing.
In this way, the sensation of color is produced by rays of light reflected or transmitted by an object.
Understanding the Light | Photographic Technique
Lightning
At first, a ray of light can be considered an electromagnetic wave, part of the broadest series of electromagnetic waves that travel through space. Therefore, it is described by its wavelength and frequency.
Length and Frequency
In turn, the wavelength is the distance between two corresponding adjacent points in the wave pattern. Likewise, frequency refers to the number of waves passing through a given point, every second.
Therefore, the product of the wavelength by frequency is equal to the speed of the wave.
The spectre
On the other hand, the electromagnetic spectrum extends from wavelengths from 0.0000001 nanometer (nm) to 1000 km.
What we call light is the visible part of the spectrum, from approximately 400 nm to about 700 nm. Taking into account that 1 nm is equal to 1/1000000000 m, it is clear that the visual spectrum represents a very small part of the electromagnetic spectrum.
Below 390 nm is the ultraviolet (UV) radiation range and above 760 nm is the infrared (IR) range. Therefore, UV and IR radiation are not visible.
In digital cameras, charge-coupled device (CCD) electronic sensors and the complementary metal oxide semiconductor (CMOS) semiconductor are sensitive to infrared rays […] White light is a mixture of colorful rays.
White light
Sir Isaac Newton showed that when white light falls on a transparent glass prism, it is not only deflected, but also refracted in many colored rays: red, orange, yellow, green, blue, indigo and violet.
The magnitude of the refraction depends on the wavelength of the beam. This showed that white light consisted of rays of different wavelengths, which correspond to the colors that we see in the spectrum (LANGFORD, 2013, pp. 2,3).
The figures below illustrate the wavelength and the incidence on the prism denoted by LANGFORD (2013):
Light wavelength | Photographic Technique
Light through the prism, generating colors in the spectrum visible to the human eye
Therefore, if the eyes perceive objects from the reflection of light, it is from the entry of that same light through the camera lens that we register and perceive the information contained in the images.
This is just an overview | Photographic Technique
Although you can delve into the advanced physical concepts of understanding the incidence of light on objects, the purpose of this article is to propose an understanding of the effects of illumination through your camera and the responses it offers when recording images.
However, throughout other articles on photographic technique that I will publish, you will see that light is extremely important to operate the camera regardless of the modes of use, whether they are automatic or manual.
Different types of light during the day | Photographic Technique
First, in practice, compare the camera's light perception to the human eye itself. A clear and sunny day seems to reveal much more colors and details than a rainy evening.
Likewise, looking directly at the sun will cause you to have blurred vision for a few moments, due to the excess light received by the cornea, which must distribute this light wave to the retina.
Just as our eyes have, in the pupil, the movement of opening and closing by measuring the light input, so it is with the diaphragm of the camera.
Therefore, when photographing, remember that light (and how to administer it in the equipment), as well as in our eyes, is what makes the difference in the results.
A photo recorded in the morning light will allow different results of the same image recorded at sunset.
Likewise, pointing the camera directly at the light will make it “blind” instead of recording the image.
However, a photo taken at night, without the aid of extra light, will reveal less detail than the same image produced on a sunny day.
Anyway, we will meet in the next article on photographic technique.
So, did you like the article and want to contribute a coffee of thanks? Make your contribution through the QR Code below. Help the Foto Blog that helps you. Any value is welcome! A coffee is R$2 here, for example.
Related articles
| Photographer | Photography | Light | Photographic Technique | FotoBlog | Understanding the light | Home
