Seasonal Variations in Aerial Mapping

Summer Map, 10-acre site

Summer Contour Map, 10-acre site

Seasonal variations are an important consideration for mapping your property or structure. For summer mapping, that is the late spring to early fall, the landscape is alive with all the vibrant colors that make for great mapping photography. Although the winter months are less colorful, there are significant advantages to these maps as well.

Summer Mapping

Summer mapping is ideal for showcasing properties and structures, especially for real estate sales. Overhead maps capture the properties with beautiful colors, not to mention stunning detail. (Think of Google Maps, but with super high resolution sufficient to see small objects, such as people and animals.)

All of our map products include geoposition and altitude information, so features such as a structure’s location and height can be measured. Our map products are referenced to sea level, in units of either feet or meters. Position and altitude information are available by just clicking the desired point.

The drawback to summer mapping is that vegetation and leaves hide the landscape that lies below.

Winter Mapping

Winter mapping is ideal for topographical charting of land features otherwise masked by vegetation and leaves. Our mapping software can “see” through naked trees and capture much more of the land features otherwise obscured in summer.

Developers of properties use our topographical products to design projects and estimate their costs. The three most common map products that aid in their decision making include:

  1. Contour Maps. We develop contour lines at the interval specified by our client. They can be at any interval, such as 50 feet, 25 feet, 10 feet, etc., and any unit, such as feet or meters. We have advanced post-processing techniques that we use to overlay contour maps onto our color maps. Examples of our composite maps are shown in these summer and winter pictures.
  2. 3D Object Maps. When opened in an object viewer, these maps provide the client with a look at the property from any angle (both above and below) the image. These full-color images provide height and perspective information of landscape and structures.
  3. Point Cloud Maps. These maps provide 3D views of the map image. They appear as a cloud of points, but each point has position, altitude and color information. The real power of these maps is their ability to see landscape underneath the trees and give the project engineer detailed information on features such as mounds, river banks, small structures, etc. Any particular map section can be selected and viewed. The selection can be rotated and zoomed to view the landscape features better than an in-person survey.

For more information on precision 3D mapping, please read our June 12, 2020 blog.

Mapping Challenges

Winter Map, 10-acre site

Winter Contour Map, same 10-acre site

Our aerial drones take overhead photos shooting straight down and in rectangular patterns. At a flight altitude of 400 feet, the ground resolution is typically 1.25 inches per pixel and the resulting map size is approximately 4 megapixels per acre. OK, this is some serious resolution!

However, there are certain areas that don’t resolve well in aerial maps. Water features and non-distinct land features may be difficult to resolve because discernable points cannot be identified or they’re in motion. These challenges are minimized with high overlap photography. That is, overlapping the photos at 90%. (This means taking 18 photos per acre.) Even at high overlap settings, there still may be features that don’t resolve well, such as bodies of water.

Why? Map making software identifies overlapping pixels to determine their exact position in space. At a 90% overlap setting, a single pixel may have as many as 100 look angles, where each angle helps to establish that pixel’s exact position. Errors in calculating these angles lead to errors in the map’s presentation.

Map processing generally goes well at 90% overlap, but can degrade at lower overlap settings, wind conditions, water features, and non-distinct land features. Winter mapping is usually more challenging because land features can be drab and non-distinct.

Which Season is Right for You?

We wrote this blog to take out some of the mystery of good map making techniques. At FAD-Photo, we have developed many photo maps and know how to set up your 3D map products regardless of season.

Flying Your Drone Indoors – What Could Possibly Go Wrong?

Flying Indoors

Who Is Your Insurance Company?

Flying your aerial drone inside a covered structure requires safety equipment, special settings, and a high degree of skill. This subject has been explored by a number of other bloggers, so we’ll summarize their recommendations and present a few of our own.

The FAA Does Not Have Jurisdiction over Indoor Flying

Part 107 doesn’t mention flying indoors because these areas are not considered navigable air space. However, there are a number of applications for indoor flying, including real estate photography, conventions, games, and drone competitions. Such applications require special considerations by the pilot. We’ll cover several in this article.

Insurance

When flying indoors, there’s significant risk that your drone will get damaged, harm people, and/or damage property. Therefore, check with your insurance company to see if indoor flight injuries and damages are covered.

Many drone pilots use Verify, now Thimble, a popular pay by the hour insurance company, which specifically excludes coverage for indoor flying. Our own insurance company, Global Aerospace, excludes coverage for competitions, but otherwise appears to cover indoor operations (per my agent). This gets confusing, since Thimble contracts with Global Aerospace. So, read your policy carefully to ensure you’re covered for flying indoors.

Tips for Flying Indoors

  1. Always use propeller guards to reduce injury and damage.
  2. Turn off GPS positioning. Interference or loss of signal can lead to unintended drone movements. For certain DJI drones, this means turning off P mode, and using ATTI mode instead.
  3. Related to 2, don’t use automated flight settings such as tracking or waypoints.
  4. Turn off obstacle avoidance. Although vision systems are excellent for outdoor flying, they can lead to stubborn flight control indoors and possible human error through over-reaction.
  5. Use beginner mode, if your flight controller supports it. Flight control stick sensitivities are decreased.
  6. Avoid ceilings, walls, and other flat surfaces. Prop wash causes unpredictable flight behavior.
  7. Turn off automatic Return to Home. If possible, set loss of signal action to hover in place.

For additional information, please refer to:

Drone U

Pilot Institute

Dronegenuity

Alternatives to Flying Indoors

Indoor photography can often be done just as effectively with a camera mounted onto a pole, rather than using an aerial drone. For example, mount your camera onto a glide stabilizer and walk your camera through the desired area. (We use our Samsung S20+ cell phone on a DJI Osmo for these shots.) Reduce camera shake with your video processor’s image stabilization filter.

This same technique can be used outdoors as well. A client once asked us to survey an asphalt road, suggesting that we fly just below the tree canopy. They were happy to learn of a much simpler method to mount a camera in front of and above their truck to capture their footage.

However, the cell phone/Osmo solution doesn’t work in high winds. For example, I once tried this technique from the open cockpit of a biplane but the 80 mph wind overpowered the Osmo. That approach was an epic failure, but salvaged by holding the cell phone and stabilizing the video in post processing.

When there’s no other solution than flying indoors, then we advise extreme caution, following these tips, and checking your insurance coverage.

DJI Phantom 4 Pro Yaw Drift

Phantom 4 Pro Yaw Drift

Compensate P4P Yaw Drift

What causes the Phantom 4 Pro to drift in yaw (heading) during programmed flights? This appears to be a common thread in a number of blogs and is a problem we’ve also encountered. As you know, I like to take on the hard problems, think them through and develop solutions. In this blog, I’ll offer ways to measure the offset and a method of compensation.

As I stated above, this is a common problem, but no one that I know of has determined the cause. Please comment if you have a better explanation and I’ll update this blog.

Are other aerial drones similarly affected? Please comment, I’d love to hear from you.

We See Yaw Drift in All of Our Programmed Flights

The yaw drift that we’ve encountered with our Phantom 4 Pro V2 is much more significant than crabbing (please see our April 28, 2019 blog on crabbing). Our data files indicated that the crabbing effect is around ±1.5 degrees, and is largely compensated by the drone’s flight controller. However, our measured yaw offset runs as high as 30 degrees, sometimes more.

Of note, from our data files we plotted the GPS position, which showed the drone stayed on its programmed circular path and its heading was tangent to the circle.

Measuring Yaw Offset

We program almost all of our aerial drone photography sessions, so when the drone’s camera offsets then it’s pretty obvious in the recorded video. A simple method to measure yaw drift is to record a Point of Interest video. That is, to run a circle around a point with the camera pointed at the center. A large radius allows the drone to be operated at maximum speed (we used 1000 feet radius and 21 mph in our test runs), where the drift was quite noticeable.

For example, print out a Google Map of the test site; then graph the video’s centerline of sight at 15-second intervals. You can measure the yaw offset with a ruler for distance, and a protractor for angle. E.g. measure the distance/angle from the centerline to the center point.

Graphical Data Results

Our data set included ten video runs, taken on different days so we had variations in drone speed, wind speed, and wind direction. In almost every case, the yaw drift was affected by both the drone speed and wind speed. One key measurement was the combined speed of the drone, where we found correlation between the maximum yaw drift and the combined air speed of the drone (that is, heading into the wind).

Our graphical analysis suggests that yaw drift can be minimized when both the wind speed and drone speed are less than 10 mph.

Conditions

  1. Drone: a 2-year old DJI Phantom 4 Pro V2 with an iPad 9.7-inch tablet. Yaw effects were similar for both DJI Go 4 and Litchi apps.
  2. Yaw drift appeared to be the same before and after INS and compass calibrations.
  3. We tried to force the drone’s yaw drift by hovering 5 feet above ground and blowing the drone with a fan. We blew the drone so hard that the camera’s gimbal was pushed into its stops, but it returned to linear after the wind was reduced. The drone’s airframe did tilt into the wind to maintain position, as we would expect, but it didn’t change its yaw (heading).
  4. We measured yaw drift in circular “Point of Interest” runs, where the drone’s camera was pointed toward the center and the drone airframe was flying sideways into the wind. CCW runs resulted in less yaw drift, so only one run was CW.

Conclusions

In flight, it appears that the drone’s flight controller is adjusting heading as the drone tilts into the headwind. So, if there’s a large headwind, the drone tilts more to maintain its GPS speed and it also yaws to the left. Since the drone’s legs don’t appear in the video, we conclude that the flight controller must be changing the drone’s airframe, not the camera.

Minimizing the Effects of Yaw Offset

  1. Fly your drone at a speed of less than 10 mph and when the wind is less than 10 mph.
  2. The yaw offset can be compensated by changing your programmed center point into the wind.
  3. Fly a larger diameter radius so the desired field of view is around 80% of the frame, then crop down to the desired field of view in post-processing.

This Crosswind is Driving My Drone Crazy

Heading Offset Due To Crosswind

Heading Offset Due To Crosswind

As mentioned in my 10/25/2018 blog, “Flying in High Winds – What Could Possibly Go Wrong?,” wind can affect your drone’s flight control system. In severe situations, its effects are immediately apparent on your screen, such as an image that bounces around. However, there’s another more subtle effect that can impact the quality of your videography, which you should know about.

Review of Your Drone’s Flight Control System

First, let’s review what keeps your drone stable while in flight. Today’s sophisticated drones use a magnetic compass and the global positioning system (GPS) to determine the drone’s heading and position. The drone’s inertial navigation system is always comparing its solution with that of GPS to hold the drone in position and to keep the camera steady. So, even if the wind is buffeting your drone, its control system is doing a pretty good job of holding the camera steady.

However, if the wind is high enough and the gusts strong enough, the drone’s flight control system can be driven into its non-linear region. This appears as bouncing around in the video feed to your screen and recorded images if you’re shooting video. Your only solution is to wait until the wind settles down and try again.

Wind Can Affect Your Videography in Other Ways

While flying your drone manually, you’ll probably never notice the effect of a crosswind. However, in programmed flights, such as DJI’s waypoint mode, you may notice a yawing (heading) offset while the drone is flying from point A to point B. This offset is known as “crabbing.”

Crabbing is where the yaw axis of the camera offsets from the drone’s direction of travel. Stated another way, while your drone’s course toward Point B may be on a direct heading, it offsets in yaw to another angle, typically turning into the wind.

In light winds, the crabbing effect is minor, but as the crosswind speed picks up it becomes more pronounced. Its effect on your video? You’ll notice your drone’s video image offset a few degrees from the straight-ahead direction.

What Causes Crabbing?

Your drone does a pretty good job of maintaining its heading and position along the desired track over ground. However, it still has to adjust heading to compensate for wind and stay on the objective track. When your drone adjusts the heading, its camera crabs over to an offset angle. This is simply vector math and is commonly encountered in aviation scenarios (as well as for boats in crosscurrents, etc.). Think of an airplane landing in a crosswind – notice how its angle relative to the runway is offset? That’s crabbing.

What Can I Do With This Information?

With awareness of crabbing, you can look for its effect on your videography. If it becomes objectionable then you can increase your drone’s speed (again, vector math), wait for a calmer day, or crop out some of the offset in postprocessing.

Zoom-in With a Fixed Lens Camera

Zooming In With Your Drone's Fixed Camera Lens

Zoom-in With Your Drone’s Fixed Camera Lens

At one time or another, everyone has had situations where zooming in on a video clip adds that finishing touch. Whether it’s for effect or for greater stand-off distance, the convenience of camera zoom takes your photography to the professional level.

In this blog, I’ll show you how to get Full High Definition (1080p) results at a zoom factor of 1.4x using a fixed-lens camera. This is good information for venues like sporting events and weddings, which can be recorded from the air but at a great enough distance so the drone’s presence has minimal notice. For more information on camera resolution please read my blog Setting Up Your Aerial Drone Camera.

Do I Need an Expensive High-End Drone and Camera?

Although that would be one way to get zoom capability, it can be a very expensive investment. But, let’s look at just one of many high-end drone/camera solutions:

For a modest investment of $5,000 you can purchase a DJI Inspire 2 drone, Zenmuse X5S camera, and Lumix 14-42mm zoom lens and the results will be quite professional. The Lumix lens gives you the standard camera focal length equivalent of 28-84mm. So, with 50mm as the standard for zero magnification, this camera has a zoom range of 0.6x wide angle to 1.7x telephoto. Remember these numbers.

Is There a Less Expensive Alternative?

There’s another solution that is far less expensive and provides excellent results. Many drones on the market can record Cinema 4K video, which has a resolution of 4096×2160 pixels. However, most users are satisfied with a Full HD resolution of 1920×1080 pixels.

What these numbers mean is that to get a digital zoom capability, you can record video in Cinema 4K mode, which leaves plenty of resolution to render any portion of the frame in Full HD. Rendering the video is done in post-processing, where video clips are transformed into the finished video.

For example, we can use our drone to record the desired scene in C4K mode. We start with the equivalent wide angle focal length of the camera’s lens, which is 35mm (0.7x). Using post-processing software, as much or as little of the C4K image can be cropped for the desired magnification. So, when your video is captured in C4K, you can select a crop “window” of up to 50% and render your new “zoomed-in” video in beautiful FHD. In other words, you get a full-definition 1920×1080 pixels! For this level of cropping, you achieve a zoom factor of 1.4x, equivalent to a 70mm telephoto lens.

Compared with the $5,000 solution, which zooms 0.6x to 1.7x, this digital zoom technique gets you 0.7x to 1.4x.

Any More Slick Ideas?

Two for sure . . .

  1. If you want even more zoom, just crop to get the desired magnification. There’s no limit to how much you can crop, though you will start to see the results of lower resolution. For example, you can crop at 25%, which gives you a zoom factor of 2.8x (140mm telephoto) but the resulting FHD video will display a lower resolution of 1024×540 pixels.
  2. Any method of zoom will increase the image’s sensitivity to camera movement. So a small and acceptable level of vibration at 0.7x may be objectionable at 1.4x. Unwanted vibration can be minimized in post-processing using image stabilization. For more information please read my blog Video Production and Post-Processing.

At FAD-Photo, we use the DJI Phantom 4 Professional V2, which provides a highly stable platform capable of stunning high definition photographs and videos. We have mastered the art of taking C4K videos and using our post-processing software to minimize vibration and render FHD videos.

We deliver the results you would expect from a professional aerial drone photography service! For more information, please refer to our Aerial Drone Photography and Video Services page.

Setting Up Your Aerial Drone Camera

Aerial Drone Camera Options

Aerial Drone Camera Options

Video Formats

When you set up your aerial drone camera to take videos, the first thing you’ll want to do is to select the American standard of NTSC (National Television System Committee).  Your other option is PAL (Phase Alternation by Line), which is more common in Europe, Asia, and Africa. A third standard known as SECAM is also common in Asia and Africa, and your drone may offer it as well. When in the USA, select NTSC. The main difference is frame rate where the American standard is based on 60 Hz and the European standard is based on 50 Hz.

Among your camera’s setting options, you’ll find video size, which allows you to select format and framerate. You can select from 4k for the UHD or Ultimate High Definition (think of Sony’s 4k digital cinema in your movie theater), 2.7k and 1080p (also known as FHD or Full High Definition), and 720p (also known as HD or High Definition).

I recommend setting your video to 1080p, which has a frame resolution of 1920×1080 pixels, and is standard among televisions and computers. Unless you have a requirement to use higher resolution, then 1080p is the standard for you. Higher resolutions, such as 2702×1520 and 4096×2160 are gorgeous if you have the hardware to play them. Their downside is the increased amount of time required to render in video editing software. Another downside is stutter when playing them on less than state-of-the-art hardware.

Recently I compared several of the UHD and FHD video formats and found that my computer monitor displayed all of them, but stuttered when the source was 2.7k or higher. I couldn’t tell any difference in their resolution when compared with standard 1080p, but that would be expected with a 1080p monitor. There was also some stutter when I played a 1080p video at 60 frames per second.

For most videography applications, I recommend using 1080p at 30 frames per second. Eventually the market will move to 2.7k and 4k resolutions, so you should be ready to switch when that time comes.

Photo Formats

Common formats for aerial drone cameras include 12MP (4000×3000 pixels) and 20MP (5280×3956 pixels), which are sufficient resolution for super fine-grain pictures. I have found that the resolution of the sensor is typically greater than the limitation placed on it by the camera’s optics.

Check it out for yourself by blowing up an image in your favorite photo viewing software. You’ll see the image is blurred from pixel to pixel, which was caused by the optics, not the sensor. This is why you want the most direct path for light to enter the image sensor. Due to their small size, these cameras (and their filters) pick up finger prints and smudges that will reduce the resolution of your camera. Inexpensive filters are another contributor to lower resolution.

Three-byte color granularity is known as 24-bit color because there are 8 bits per primary color.  It’s also known as “True Color” or “16.8 million colors” since 2 raised to the 24th power is 16.8 million.  Using our drone’s 12MP image as an example, the resulting image file is 36 million bytes (or 34MB).  Fortunately, cameras compress the images and reduce their file size to perhaps a tenth of their original size. You’re probably already familiar with the common file compression standard created by the Joint Photographic Experts Group and known as JPG.

A drawback of the JPG compression standard is that certain pixels are selectively thrown out. The loss in fidelity is usually negligible. However, the compression process is not reversible so some image quality is permanently lost.

For optimum results, professionals use the camera’s raw mode, which compresses image files without throwing out any pixels. The resulting file sizes are 2-3 times the size of a JPG file, but there’s no sacrifice in image quality. DJI’s aerial drone camera options list RAW, but download in Adobe’s Digital Negative (DNG) format.

For most photography applications, I recommend using the JPG format due to its high popularity. For those special shots (or client requirements) then select raw mode.

Other Aerial Drone Camera Settings

Settings for exposure value, contrast, saturation, color filter, etc. are also available for the experienced photographer. Default values will usually suffice for the casual photographer, but when you’re looking for more control you’ll find it under these settings.

Fly Safe!

The Exciting World of Panoramas

Fourteen Individual Photos Were “Stitched” to Make This 360-degree Wide-Angle Panorama

How often have you wished for a wider angle lens to capture your subject of interest? Or have you seen wide angle panoramas and thought to yourself “That’s cool, I wonder how they did that?” Let’s take a look at how to make panoramas that provide a poster-size photo of your subject or immerse yourself into a 360-degree wide-angle, or better yet a cylinder or sphere. Virtual immersion is some of the latest technology for real estate marketing, travel, and personal entertainment.

Rules for Panoramas

Depending on zoom setting, eight pictures should be sufficient for a 360-degree panorama. Do some test runs to practice your technique. The general idea is to take a series of horizontal pictures that overlap 10-20 percent. Ditto for vertical panos. Add a row of pictures above (horizon) and below (ground) for a larger panorama. And always:

  • Take pictures from one position (technically, the position of your lens)
  • Lock your camera’s exposure for all pictures

Making Your Panorama

The term for assembling the individual shots into a panorama is “stitching.” Basic stitching software includes Microsoft’s ICE (it’s free). For more professional results, programs such as PT GUI Pro automatically blend the images. Think of the blue sky that varies in intensity from shot to shot. Automatic blending provides a pleasant transition from lighter to darker shades of blue.

Can I Control Where The Stitches Are?

Good stitching software will give you control over where the images get stitched. Say you have 20 degrees of overlap, but an object is in motion in both images. For example, a car is in position A in one image and position B in the other image. You select which image to dominate through masking, and the other will disappear. As long as you have adequate overlap, the images can be successfully stitched.

Spherical Panoramas

Use the software’s “Layers” option to create the file set for a spherical projection. Then use Tools/Publish to Website, add these files and hit the convert button to build the web file set. Upload these files to a web folder and copy the link to the master file “name.htm”. (You will see a lot of image files, each with small portions of the pano; this is normal.) Insert the link wherever you desire and the spherical panorama will come up when viewed in your browser. Use your mouse to move around the pano. This is how the professionals do it for real estate portfolios, FaceBook, etc.

Here’s an example of a spherical panorama we made with 26 images: Monument Valley

Other Practical Uses

As I mentioned above, panoramas can be used to make super wide angle photos. If you can’t position yourself far enough away from your subject, then take multiple images of it and stitch them together. Do you have a large print or poster that’s too large for your scanner? Scan it in sections and stitch them together for a high-resolution image file that’s much better than taking a picture.

Fly Safe!

Balanced Propellers Will Reduce Vibration in your Aerial Drone

Use an instrument like this to ensure your drone has balanced propellers

Balance Your Propellers For The Smoothest Possible Flying Experience

Balanced propellers will reduce the vibrations that transfer to your flying camera as these small movements can result in blurred stills and shaky video.

How Can I Improve the Quality of My Drone’s Photography?

Drone manufacturers have fairly good quality control for their airframes but like any airborne device their smoothness depends on proper balancing of the rotating components. In our case, that would be the propellers. We’ll assume for the moment that the motors and propellers are running true and aerodynamically balanced. More on that below.

First, Why Should the Propellers be Balanced?

Well, why do drivers balance the tires on their cars? Experienced drivers know that unbalanced tires lead to vehicle vibrations when their speed picks up. The same holds true for drone propellers. When one part of the propeller is heavier, the spinning mass delta will cause vibration that increases with speed.

The Solution is Propeller Balancing

To balance the propellers, you’ll need to purchase a balancing kit; example in the picture above. It works by attaching a rod to the propeller and the pair is then balanced on a very low friction support. Any propeller imbalance will cause the propeller to roll until the heaviest part of it hangs below. Balance is achieved by adding or removing material until the propeller is stable.

Here’s the How To:

Place the propeller so it’s horizontal and watch for one side or the other to dip. Then sand/scrape off a small amount of material from the heavier blade such as on the bottom side near the tip. (Or add a little scotch tape to the lighter blade.) Horizontal balancing will take out most of the vibration.

Vertical balancing is next. The concept here is that whatever imbalance that remains is in the hub. Place the propeller so it’s vertical and look for motion. Balance is again achieved by adding or removing material until the propeller is stable, but this time it’s at the hub. If needed, sand/scrape material from the heavy side of the hub, between the propeller blades. This step may take longer because more material typically needs to be removed.

Your propeller is properly balanced when it remains stationary on the support no matter which position the blades are placed.

How Do I Ensure the Propellers are Running True?

Great question and easily answered! Start your drone on an elevated surface, such as a table, but don’t take off. Then observe the blade tips, looking for spread. There will be little to no spread if the blades are running true, which means they’re aerodynamically balanced.

If there’s spread between the tips, then the blades have different amounts of lift or the motor/shaft are bent. This means that your propeller is aerodynamically unbalanced, causing vibration. Typically, the culprit will be just one of the propellers so you can rule out a bent motor by swapping the propellers (e.g. exchanging one black hub propeller with the other). If whatever spread you saw on the one side does the same thing on the other, then the propeller is bad.

Balanced propellers will lead to the smoothest possible photography with your drone. Whatever residual vibration that appears in your video can be taken out with post-processing software.

Fly Safe!

You Don’t Have to Know Trigonometry to Plan a Drone Shoot, But It Helps

Image of trigonometry for a drone shoot.

Learn Useful Information By Applying Your Camera’s Field Of View Specification

Here are some tips on how a little trigonometry can help you to improve your drone shoots. Most Virginia drone pilots can fly to a position that “looks right” in their display for taking photos and videos, but what about those large jobs, such as a hundred-acre tract of property?

I recently had a commercial session involving the marketing of 116 acres of undeveloped land. My usual preplanning (and pre-programming the aircraft) was a little more challenging because I wanted to fly at the right altitude, the right speed, and the right camera tilt in order to minimize the “trial and error” approach to videography.

I’ll be happy to talk off-line about the actual formulas, but to keep this post as brief as possible I’ll just outline the principles. The fundamental information you’ll need is your camera’s field of view (FOV) and the frame’s aspect ratio. For example, the DJI Phantom drone’s FOV is 94 degrees and its aspect ratio is 4:3 for photos, and 16:9 for videos.

For 4:3 photos, the trig results are approximately 75 deg horizontal FOV and 56 deg vertical FOV. (Approximate because this is a two-dimensional approximation of a 3-D device.) These results are shown graphically in the figure above. For 16:9 videos, the horizontal FOV is about 7 deg wider (82 deg), and the vertical FOV is about 10 deg narrower (46 deg).

With this information, you can calculate the field of view for any given distance. Say you’re shooting a photo straight down from an altitude of 100 feet. Using the sine and cosine functions, the horizontal FOV is 122 ft and the vertical FOV is 95 ft – or – a rectangle 122 x 95 ft. This is suitable if your subject, say a house, is around 60 ft wide. This ratio stays the same, so at a distance of 200 ft, the rectangle scales up to 244 x 190 ft.

Another useful angle is the tilt required to put the top of the frame just below the horizon. We found out above that the vertical FOV is 56 deg. With the camera’s tilt at 0 deg, the horizon is centered in the view. Therefore, the top and bottom of the view are at 0 deg plus/minus 28 deg. So, in theory a camera tilt of -28 deg should put the horizon at the top edge of the camera’s view. For 16:9 video, the horizon (again in theory) is at about -23 deg. In practice, I use a tilt of -30 deg for photos and -26 deg for videos to ensure landscape pictures aren’t turned into silhouettes by the bright sky.

Another tip: Use algebra to solve the time required to run a certain distance at a given speed. This will help you determine how much air time will be required per run and, thus, how many batteries to bring.

These concepts are approximate and you may come up with different results. Regardless, a reasonably disciplined approach will help you plan your flying sessions.

Fly Safe!

Drone Flight Profiles

This is a recent video of pre-programmed drone flight profiles that showcases a residence for real estate marketing. These are just example profiles and we are by no means limited to what you see here. The sky’s the limit when it comes to aerial drone photography.

Notice the production quality of the videos. The smooth flight paths and camera tilting are all controlled by pre-programmed flight profiles. We do this with special after-market drone flight control software along with advanced video processing, which together reduce the residual shake and vibration. The results are breathtaking videos, ideally suited for professional publication.

The video speeds were adjusted to keep this film clip less than 90 seconds. For your video, you have as much say as you want in how the video will be edited, including brightness, contrast, color saturation, playback speeds for each segment, start points, end points, introduction, credits, logos, etc.

When You Work With Us

We’ll provide you with a number of our “standard” drone flight profiles, review how you want your shots to be captured, and program our drone software prior to arrival on site. We are by no means limited to these flight profiles; the possibilities are almost endless. All this can easily be coordinated by phone or e-mail. When you use our drone services, you have as much say in the process as you like.