The Uses UAV Digital Aerial Photography – What Pictures Should You Take?

UAV aerial photography has many applications, and each requires a different type of picture. Aerial photography is very flexible, you have complete control over the angle, lighting, and overall appearance of the images you are taking. This flexibility allows it to be used for a variety of projects, from aerial surveying to making inspections of equipment, or even promoting real estate. All of these projects should be approached differently – listed below are the general approaches suitable for each.

UAV Aerial Inspection of Equipment

UAV’s are excellent tools for inspecting industrial equipment. In many cases, the area that you need to look at is inaccessible or hazardous. Sending in a UAV gets you the pictures you need, without any risk to staff members or property.

So how do you get an adequate image of equipment? Your goal is simply to capture as much information about the target object as possible, ideally, in several images or in a video. Choosing between still pictures and video can be difficult, but in general, still pictures are better for the inspection of equipment. Video cameras increase the chances of you getting what you want to see in the image, but the resolution of each frame is much smaller than with a comparable still camera.

If you are using a still camera to do the inspection, the best strategy is to get as many pictures as possible. Even though the Draganflyer X6 wireless video receiver will give you a general idea of how to position the helicopter, vibrations, wind gusts, and other movement will make affect each image. By taking as many as possible during a flight, you are guaranteeing that at least a few of them will be suitable for your purposes. The objective is not to obtain perfectly aligned or tilted images, but to get a sharp and well focused picture, that contains everything you are interested in inspecting.

The unprocessed digital image of a natural gas compression station taken with the Draganflyer X6 UAV

In many cases, the images you obtain using this “shotgun” effect will not be perfectly horizontal. There is nothing wrong with this. If your objective is to get visual information about the overall state of your subject, then you can do so without worrying about the camera angle. If you need to publish pictures that are not completely horizontal, your best option is to crop them digitally, using software such as Adobe Photoshop®.

The picture on the left was used for the aerial inspection of a stack where natural gas is compressed (click for a larger version). When the image was obtained, winds were gusting in excess of 30 kilometres per hour (18 miles per hour). The autopilot was able to hold off most of the wind’s interference with the image, but it was left with approximately a 5 degree tilt from the horizontal. This is of no consequence, because cropping the image yields the following:

A cropped image of the same tower taken with the Draganflyer X6 UAV

We can clearly see the top of the pipe in this image, and everything that is occurring around it. This is more than sufficient for a quick visual inspection.

UAV Orthophotography and Aerial Surveying

Orthophotography is aerial photography done with the camera facing straight downwards. This creates an image where the scale is constant throughought. Because the scale does not change with position on the image, you can make accurate measurements of angles, areas, and distances using relatively simple methods. When doing orthophotography, make sure that the camera is as close as 90 degrees to the ground as possible. We have written an in-depth how to for doing orthophotography with the Draganflyer X6 UAV, feel free to read it if you want to learn more.

UAV Aerial Photography for Aesthetics and Real Estate Promotion

When taking aerial pictures for real estate promotion, the aesthetics of the image matter more than anything else. Your goal is to take a single picture, that at a glance, shows potential customers the entire property in a very positive way. People should be able to look at the completed image and be pleased by its beauty, elegance, or simplicity. How do you do this? There is not a really simple answer, but here are few general rules to follow when taking pictures for aesthetic purposes:

• The Rule Of Thirds – Generally, people find pictures of an odd number of objects more pleasing than pictures of an even number of objects. When presented with an even number of objects in a group, the brain tends to look for asymmetries in the image, decreasing it’s aesthetic appeal. The same problem occurs when the primary focus is placed in the direct center of an image – your mind assumes that it’s perfectly centred, and looks for misalignments. You can avoid these problems by putting the focus of your image near the first or last third of the field of view. Doing this removes the sense of symmetry, and improves how the overall image appears.
• Level and Well Focused – Keep your images level, and be sure to allow the camera time to focus before moving. Ensuring that all of your aerial pictures are level is difficult, so take many of them while in the air. Out of all the ones that you obtain, at least a few will be excellent.
• Distracting Objects and Highlights – The last thing you want in promotional images is distractions that take away from the images main focus. Try to avoid including objects that stand out to much, such as reflections, highlights, and those that are brightly colored.
• Lead the Eye – One technique used by photographers is called “leading the eye”. By arranging visual cues in the image, you can guide the viewer to the main focus. This makes the image both more aesthetically pleasing, and more interesting for the person looking at it. Rivers leading to mountains, highways leading to houses, and green lawn leading to a house are all examples of this technique.

If you’re interested in learning more about aerial photography, or photgraphy in general, we highly reccomend reading www.photography-basics.com.