Some people often wonder with amazement when they contemplate the clear sky: What produces this beautiful color in secondary sunset, and why the sky is in blue color? Of course, the blue color with which the planetarium is pigmented is not arbitrary, and it is not a natural coincidence, but there is a scientific reason behind this phenomenon, how can we explain it on scientific grounds in light of what we have learned about the reflection of light?
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Why the sky becomes red in the secondary sunset?
The reason for the redness of the sky at sunset is due to a phenomenon called Rayleigh scattering. When photons of sunlight pass through the atmosphere, some of these photons are absorbed by atmospheric gas particles. This causes these particles to excite higher energy levels, but they soon return to their original energy levels and release the energy they absorbed in the form of other photons.
Also read: what is white balance in photography and how its used in a camera
We must know that there is a main condition that must be met in order for the particles to excite, and this condition is that the frequency of the photon is equal to the resonance frequency of the gas particles. Indeed, this condition is fulfilled between the particles of atmospheric gases and the blue light from the sun, and the condition is also fulfilled in a smaller percentage with green and much less with the rest of the colors. For information, this is the reason for the blue color of the sky, where the blue rays of the sun are scattered in all directions, so the sky appears blue
When secondary sunset occurs the same thing happens, but with the passage of sunlight at a thickness greater than the atmosphere, because its rays do not fall perpendicular to it, so it happens that the blue light is scattered and a good proportion of the green light, but because it crosses a large thickness, it does not reach the earth and this leaves room for the part red, orange and yellow sunlight can reach the earth without problems, so the sky appears red.
how to use the light you have to take your photos
The position of the sun in the sky plays a huge roll in the kind of light available to work with. If it were just below the horizon everything would have a beautiful blue cast. If it is at its peak it will create harsh shadows. Knowing the status of the sun will help you in advance makes planning much more easier.
The earth is tilted on its axis as it rotates around the sun. This is what creates the seasons. While the sun will always rise in the east, and its seat in the west, how height it rises and the west it determines depends on the time of year. Some photos can only be taken at certain times of the year.
There is a lighthouse near me that I want to capture as the sun rises above it. During the summer, the sun roses too north for me to get the image that I want. But in November and December, it will go up exactly where I want it. How do I know that? SunCalc.
Introducing Suncalog
Suncalc is a web-based app built on top of Vladimir Agavunkin’s Google Maps. Suncalc shows the path of the sun throughout the day to anywhere on Earth in no time. Suncalc also calculates the times of sunrise and sunset and a different scale of twilight so you know how much and what kind of light you have to work with.
Suncalc is great for planning photo sessions at sunrise or sunset. If you just want to take pictures during the wonderful natural light of a blue hour or take the time lapse between setting the sun in the sea, Suncalc can help you decide when and where to work.
1. Find your site
SunCalc is simple to use. On the map, zoom in to what ever photography you are planning. Drag and drop a pin to set your location.
The yellow line represents the direction of the sunrise, the orange line represents the position of the sun at the specified time and the red line represents the direction of sunset.
The closer the arc is to the pin, the higher in the sky the sun is. The two gray lines represent the range throughout the year.
To get a prediction at any time in the future, enter it in the dialog box at the top. Sonalk will update the screen automatically.
2. Plan sunrise and sunset photos
Suncalc is very useful for choosing areas for sunrise and sunset photos. I hate waking up early unless to take pictures. Until that could also be a struggle. With Suncalc you can save yourself valuable time on site, and get more time in bed by planning your photos ahead of time.
If there is a specific landmark you want to photograph at sunrise or sunset in my case it’s Billy Lighthouse Suncalc is a great way to look at possible angles. Because I’m familiar with the area, I know I can get a clear view of the lighthouse from the cliffs to the west of it. During the summer, however, there was no way for me to get an angle that included every lighthouse and sun the way I wanted. This month I can get just a picture I want of the slopes. On the day of the winter solstice I am even able to get a picture of the hill above the lighthouse.
This type of pre-shoot planning makes your job on site easier. If you think of any shoot that involves a lot of additional like interval gear and long exposure – knowing that you’ll be able to get the images you want is important. There is nothing worse than pulling 20 kilograms of gear and a site assistant only to find that the sun is 30 degrees away from where you need it to be.
3. Planning for the day time photos
Suncalc is also useful for planning daytime sessions. If you are going to take pictures in a specific location, knowing what direction the sun is going to come from can help you prepare. It can be difficult to take large photos in the harsh shade of the midday sun but you can usually still get great shots in the shade. With the sun, you can work where you will be
For landscape and architecture photographers it’s also great. They have a lot of flexibility when working in direct sunlight, especially when the sun is behind them. If you plan on capturing a specific building, the sun can help you work out what angle will produce the most flattering photo even in the middle of the afternoon.
Dispersion principle
Because the gas molecules in the air absorb part of the sun’s rays, (not all of them), there are seven colors with different frequencies and wavelengths, and the part that the dust particles absorb, then reflect and disperse is the blue color with a high frequency and short wavelength more than the rest of the colors, when rays collide the light in the particles of the gases, the blue color is absorbed greatly and then re-scattered in all directions.
So when we look at the sky as a whole we see the scattered blue color
The sky ranges from dark indigo to orange or red at secondary sunset, but we tend to think that the natural color of the sky is blue. Since the sun is the source of light on the earth, it emits white light, it is really surprising that we always think that the color of the sky is blue.
The white color consists of a mixture of the seven colors of the spectrum (red, orange, yellow, green, indigo blue, and violet, as they appear in the rainbow), which results from the different lengths of the rays that make up the light. As for the color of the visible matter, it also results from sunlight of different lengths. Some materials are distinguished by their ability to absorb, reflect or refract light in different directions. (With the exception of a completely transparent material that will allow the light to pass through as it is, as well as an effect of human vision.
And red matter, for example, if exposed to light absorbs all colors of the spectrum except for the red color, which reflects it. The purple material reflects some red and some blue. As for the black matter, it absorbs all the colors of the spectrum, and the white reflects them all.
When a ray of light passes through the air, it will inevitably be refracted to a certain degree depending on the amount of dust around it. Short waves of the (blue) spectrum are refracted to a much greater degree than long (red) waves. On clear days where dust and water droplets are few in the atmosphere, the reflection of light rays will be very limited, and thus we see the sky a light blue. At sunset, when the amount of dust in the air increases, especially during harvest days, the light scattering increases, especially the short blue waves, so that the yellow and red rays remain visible on the surface of the earth.
And if the Earth was like the moon, without an atmosphere surrounding it, the sky would always appear black, day and night.
Among the beautiful landscapes that can be seen in this life is the beautiful red sunset view.
Was the sun really red at secondary sunset
The truth is that at that moment, people who are thousands of miles away at sunset are looking at the same sun and it did not appear red to them.
So why is that ?
The distance sunlight must travel through the Earth’s atmosphere produces the colors of sunset, since the lower it decreases.
The sun has increased the distance of the atmosphere through which light travels.
Since sunlight is a mixture of all the colors of the spectrum, it appears white to us, it also passes through air, dust particles, water vapor and other impurities, which leads to scattering the different colors of light in different degrees, as the atmosphere scatters the violet color.
Blue and green are more scattered than red and yellow; As a result, when the sun goes down, we see a reddish color.