There are several new ways and methods that photographers use to make their work stand out from the rest. Over time, these methods become common practice in the field, and even photography enthusiasts try them out from time to time. But then comes a rare and amazing trend that trumps them all, and aerial photography is one such trend.
Aerial photography isn’t something that was adopted recently, but it has become more common and mainstream in the past few decades. It enables photographers to give their images a new perspective and more depth as well. Moreover, viewing landmarks, sceneries, buildings, rivers, and much more hundreds of meters above the ground is more exciting than viewing them from the ground.
Aerial photography is being used in several different types of photography. Moreover, it is also being used for other applications in various industries. In this article, we will discuss the fundamentals and concepts related to aerial photography.
What is Aerial Photography?
Aerial photography refers to the process of taking photographs from the air through various methods, such as aircraft, helicopters, hot-air balloons, and drones. It requires a high-quality camera with high accuracy so that you can take pictures with impeccable clarity. Aerial photography has been tried out by photographers and experts back in the 19th century, and they used helicopters and balloons to achieve the height needed to take a high-resolution and clear photograph.
Over time, aerial photography became evolved, especially with the invention and development of drones. Although they have made life much easier for photographers, aerial photography can still be very challenging for them. There is a lot that they have to consider and take care of before they can get the perfect aerial shot. Plus, if they are using a helicopter or hot-air balloon, they also need teamwork and coordination.
What are the Applications of Aerial Photography?
There are several applications of aerial photography, including commercial, industrial, agricultural, and several others. Due to the increased availability and affordability of drones, people have started using them for public and private purposes as well. One of the most effective applications for it is in developing topographic maps for getting a layout of a specific area. Most content creators also make use of drone photography to capture the entire landscape of the place they are visiting or spending their holidays in.
Apart from this, aerial photography is also used to get an idea of the local conditions, and several official departments and agencies make use of it for land use, forestation, urban planning, and much more. They make use of remote sensing, along with high-precision cameras, to get a lay of the land and also map out the landscape much more accurately.
In modern filmmaking, aerial photography is used to capture breathtaking shots and provide viewers with a captivating movie.
These aren’t the only applications for aerial photography, and some more of them include oil and gas surveys, surveillance, advertising, electrical inspection, environmental studies, etc.
Categories of Aerial Photography
Various types of aerial photography are divided by experts into different categories, including the camera axis, the scale of the image, and the type of film used for shooting. You can choose between the different categories according to the purpose for which you want to take photographs, as well as the subject that has to be captured.
The camera axis refers to the angle from which the photograph is being taken. Furthermore, the orientation of the camera axis also leads to three types of aerial images.
- Vertical photographs: These photographs are achieved by keeping the camera axis in a vertical position. When this axis is maintained, there is little clarity in the resulting image, and a small area is covered. Usually, vertical photographs are used for mapping purposes.
- Low oblique photographs: To take these photographs, you would need to tilt the camera axis by more than 3 degrees in the direction where the horizon isn’t visible in the resulting image.
- High oblique photographs: For taking this type of photograph, you would need to tilt the camera axis by 60 degrees or more, so to cover a larger area. The horizon will also be available in these images, and it brings you more clarity and depth for identifying different features in the frame.
Your choice of the camera axis depends on your flying conditions or the features of the drone. If you are using a helicopter or a hot-air balloon, then you would find it difficult to capture vertical aerial photographs in turbulent weather conditions. Therefore, most photographers make use of the tilted camera axis that gives you a low or high oblique photograph.
The image scale refers to the width of the covered area in the image, as well as the proximity from which it has been captured. There are two types of aerial photographs that can be taken based on the scale factor.
- Large scale photographs: These types of photographs are taken when the aircraft or drone is flying at a lower altitude and the camera covers a small area. This makes the objects appear larger and clearer, and the ratio of the distance from the ground is higher. These are also known as low elevation photographs and are commonly used for mapping and measuring applications.
- Small scale photographs: These types of photographs are obtained when the aircraft or drone is at a higher altitude, meaning that a larger area is covered by the camera and the ratio between the objects in the frame and the distance from the ground is smaller. These images are suitable for applications in which the accuracy of the details of features isn’t as important.
Generally, large-scale photographs have a ratio of 1:25000, while small-scale photographs have a 1:50000 ratio.
Type of Film
Last but not least, the film used for aerial photography is divided into several categories, which vary according to the different types of applications.
Panchromatic images: These images capture all of the visible wavelengths of energy on a specific type of film. The resulting photographs are in grayscale and are mostly used for map study and surveying.
- Color photographs: This type of film is used to capture several visible bands of energy to get clear and high-accuracy images. It is used to identify objects within the covered area.
- Infrared imagery: This involves the use of infrared film, meaning that it only captures infrared waves. It is mostly used for studying rivers, lakes, forests, and other types of vegetation and bodies of water.
- Color-infrared imagery: This category makes use of infrared film and combines it with color for various purposes, including mapping of water bodies, vegetation, urban planning, etc.
- Thermal infrared imagery: It captures temperature ranges along with infrared images, and it is mostly used for weather mapping and other similar applications.
- Radar imagery: This category makes use of a special type of film that captures microwaves or radar waves, and it has a lot of distortion that needs to be cleared out. It is mostly used for weather applications.
- Spectra-zonal images: Lastly, these types of photographs involve the use of film that captures various parts of the electromagnetic spectrum, which makes them suitable for use in mapping applications.
Angular coverage refers to the different angles from which you take aerial images. This is mainly divided into four categories.
- Narrow-angle: This type of coverage involves angles below 50 degrees.
- Normal angle: This type of coverage involves a 60-degree angle precisely.
- Wide-angle: This type of coverage is used for wider aerial images and has a 90-degree coverage angle.
- Super-wide angle: This type of coverage has an angle of 120 degrees.
How are Aerial Photographs Taken?
Aerial photographs are captured by mounting or fixing the camera to an aircraft or airborne objects, such as an airplane, helicopter, hot air balloon, or drone. Some of the early aerial images were also taken by attaching cameras to kites, mainly for archaeological sites. Modern cameras can be triggered or controlled with the help of remote control or even your smartphone, which makes it easier for you to capture images without actually being airborne yourself.
Nowadays, drones are the most common method used for aerial photography. Not only are they cost-effective and easier to execute, but they also allow you to capture a larger landscape and also use different camera angles and altitudes to get the perfect shots.
Fundamentals of Aerial Photography
So far, we have discussed the basics and methods used in aerial photography, as well as the different categories that are involved in capturing aerial images. Apart from these, there are several other fundamentals and variables that you should know about because they are integral to the entire process.
Flight direction is a factor that is applicable when you are using an aircraft or airborne object and handling the camera yourself. When it comes to aerial photography, the aircraft is flown in strips over the area that needs to be captured. To ensure better handling and more clarity, it is advisable to maintain a minimum amount of strips, with the flight direction aligned with the length of the area. You can set the direction according to a certain natural or man-made feature in the covered area, which should be specified properly.
Time and Season of Photography
The time of day at which you take the images is also important to their quality and richness. As the day passes, the sun moves around and also causes the direction of the shadows to change. Larger shadows can hide important details in the area you are trying to cover, whereas smaller shadows can make certain features appear more highlighted. Experts suggest that the best time for aerial photography is when the sun is 30 degrees above the horizon, which translates to three hours before or after the noontime, according to the local time.
During this time, you would be able to avoid shadows. However, if you are looking to add more colorful hues to your images, then the golden hour is the time you should capitalize on. It refers to the hour just before sunset or the one after sunrise, and it provides you with the perfect lighting you need to capture stunning images.
The season also makes an impact on the quality of photographs that you capture. The changing seasons can also affect several factors, including light reflectance, vegetation cover, and the climate as well. Moreover, the purpose of aerial photography also dictates which season you should do it in. For instance, if you are looking to conduct mapping or a geological survey, you will need to choose a time when the ground is visible.
Since aerial photography involves the capture of images from the sky, you also have to take atmospheric conditions into account. If you are shooting in an area that has dust or smoke particles in a high concentration, it can significantly alter the contrast by scattering the light. The molecules of atmospheric gasses also tend to have the same effect.
Therefore, you should choose a time or season in which the sky is clear, and you have a look at the weather forecast for your designated area to find out when you will find the best conditions to capture images in. Choosing the pre-monsoon or monsoon season for photography is always a bad idea since it can also be dangerous for you and your photography gear.
Aerial photography is usually carried out with a multi-lens system, which allows for better accuracy and clarity in the images. Generally, a minimum of two camera lenses are combined for photographs that have a smaller area with lower angular coverage. A three-lens system allows you to capture a broader area and you can also use it to cover horizon to horizon. Moreover, it can be used for mapping, geological surveys, and other common applications.
This concludes our extensive guide to the fundamentals of aerial photography. To get the most out of your aerial photography experience, it is very important to take note of the basics and factors that we have outlined above. Most of the time, you might have to wait for a long time to get the perfect conditions for your aerial images, but the results will be worth the wait.