Close Range Aerial Imaging by Helicam

Flying Helicams For The Big Screen

2011-08-07T15:47:00.000-07:00

One does not need to be particularly prescient to see that the marriage of remotely piloted helicams and digital cinema cameras will continue to evolve and provide exciting, never before seen vantages for the motion picture industry. As interest continues to grow in this arena, the reliability, capability and associated technology will grow at an ever increasing pace. However, the primary reason for expanding use of this tech in film-making is far less complex - quite simply it is cost. It is an order of magnitude less expensive to capture a unique live action shot using a helicam for a day or two of location shooting than paying the wages of several VFX/CGI artists for several weeks.

Close-range, live-action aerial imaging and VFX/CGI are not necessarily competing interests however. One of the best, most dynamic uses of helicams is to capture the background layer of the world from above that later is accentuated through the addition of composited elements added in post production. Having this real-life template as a starting point, with all it's perfect nuances of texture, shadow, color and motion is priceless in selling the reality of a fantasy or action sequence that incorporates VFX to an audience whose expectations increase daily.

One of the primary obstacles in using helicams in feature films has been the limitation in payload capacity of the unmanned aircraft. Until now, the use of this technology has been primarily limited to flying modified 35mm film cameras with 200 ft. loads. Only recently have digital cinema cameras achieved the weight and form factor to permit efficacy on a remotely piloted helicopter. The most exciting recent development in this area is the RED Epic camera. At around 10 lbs. with battery and a prime cinema lens, this 5K camera is a god-send for helicam imaging for the big screen. While DSLR cameras like the Canon 5D MK 2 are small and seeing increasing use for television programming, the quality lags miles behind that of the Epic at present for use on the silver screen. Most seasoned DP's would not consider a DSLR for feature film-making due the the problems with aliasing, moire and rolling shutter.

Below is an example of a large industrial size helicam used to carry the RED Epic camera by Perfect Perspectives Aerial Imaging for motion picture filming. As mentioned previously, the primary benefit of this type of platform is it's power and duration. Both of these benefits have proven priceless when multiple takes are required (as they always are) and shot set up is complex. Time is money on a movie set and not having to stop flying for 30 minutes at a time is a very efficient and economical way to operate a helicam.

Environmental Considerations for Helicam Cinematography

2011-02-13T10:51:00.000-08:00

Close range aerials can be obtained in a wide variety of wind, weather and lighting conditions with the quality of the final footage being directly proportional to the severity of the conditions present. Obviously the best results will most often be achieved in near perfect conditions. The problem here is that we must work around mother natures schedule and not the reverse. Whether or not acceptable results can be obtained when the conditions are less than ideal is primarily dictated by the type and quality of platform employed, camera gimbal stabilization and the flying skills of the operator.

Wind
At present, most outdoor Helicam demo reel footage of acceptable quality will almost always have been shot with little or no wind present. For a single rotor platform, when significant winds are present, the best footage is usually obtained flying head on into the wind verses perpendicular to it for example. The winds direction is always an important consideration when planning each shot, for not only shot quality, but also approach planning in case an autorotation is required in the event of an emergency. Autorotation is the unique ability of a single rotor helicopter to maneuver and land without power. To consistently acquire usable footage in winds above 10 mph at this point in time, a large single rotor aircraft weighing at least 30 lbs. fully fitted with camera and other needed accouterments is required. In addition to needing this larger mass for overall stability, a well-tuned, gyro-stabilized camera gimbal is also required. The associated cost, complexity and skill required to fly and maintain these larger aircraft quickly narrows down the number of potential sources however.

Precipitation
If properly designed and installed components are used, it is not an issue to perform flight operations in light mist, rain and snow. Since the camera/platform is usually required at some point to engage in forward flight, precipitation typically becomes more of an issue of keeping moisture off the camera lens than creating an operational problem for the aircraft and/or operator.

Lighting
The quality of lighting (brightness) and overall visibility (lack of fog/haze) present has a direct bearing on the range or distance the helicopter can safely be flown from the pilot via "line of sight" during daylight operations. The position of the sun relative to the pilots viewpoint must also always be considered when laying out each shot. The aircraft must never be flown in a path that requires the pilot to look directly into the sun if possible. Shadows are another important consideration when shots are obtained from an aerial view. Things always look a bit different from above and shadows can quickly creep in a ruin an otherwise good take. In many cases there is ample time in a given day to film a large number of shots but the optimum window of opportunity for best lighting for each individual location is often very brief. Because of this, proper shot scheduling/planning for the lighting conditions is critical.

Flight operations during dusk, dawn and dark conditions are also possible using high intensity LED lighting systems on the aircraft. The range of operations using such lighting systems is very similar to that of daylight operations. The flight path must be carefully scoped out during the day in order to prevent collision with objects extending upward such as power lines and structures. Just as the suns position must be accounted for during daylight operations, the position of bright lights must also be taken into consideration during nighttime operations.

Dust and Dirt
A helicopter is a precision flying machine and so dust and dirt are its enemy. There are several techniques that are available to mitigate this type of issue however when the location requires operation in sandy, dirty or dusty environments. In such conditions, the rotor downwash from the helicopters blades will kick up large amounts of particulate, which, if not abated, which will find its way to the cameras lens, not to mention many of the close tolerance mechanical parts of the machine.

To summarize, it is possible to obtain close range aerial footage that will mesh with the look and feel of the particular scene in question, provided certain considerations and plans are made to account for the various environmental conditions at hand at the time of shooting.

For more info please visit http://www.perfectperspectivesaerial.com

Advanced Helicam Applications and Techniques

2011-02-05T07:11:00.000-08:00

Most Helicam aerial imaging is performed within a framework known as "line of sight" or LOS. There are several reasons for this. The most obvious being that if the pilot has a clear, continuous visual link to the aircraft being flown, it can be controlled at all times. The up side of this arrangement lies in its simplicity. Aside from flying behind an obstacle, having sudden vision problems or flying so far away as to lose orientation, there is very little that can go wrong, (aside from aircraft mechanical/electronic control problems anyway). The down side of this arrangement is that it limits the range of use to an area extending about 900 feet horizontally and 400 feet vertically from the pilots fixed position. For the majority of shots required, this is a non-issue.

The radio control systems used today are capable of transmitting a clear signal several times further than the LOS distance. The position of the pilot is also critical for optimum LOS shooting. In some cases it is most effective to place the pilot on top of a building, mobile manlift or other fixed structure to improve visual range over any obstacles.

Helicams can also be piloted directly from the cameras transmitted video signal in what is called "first person view" or FPV. While this can improve close maneuvering around obstacles and extend operational range, loss of video feed remains a significant additional risk factor however.

Recent advances in GPS based autopilots show great promise for extending the range of use well beyond the visual LOS range noted. These devices can be programmed in a manner that allows the aircraft to fly a series of "waypoints" and then return to its home position with just the flip of a switch. While this type of technology will assuredly advance the capabilities of Helicam systems, for the moment there are several major hurdles that must be overcome first. Most notably among such obstacles includes the requirement of the system to sense and avoid both full sized aircraft and ground based obstacles. Another limiting factor is a pilot is capable of executing extremely complex, continuously variable commands that, at present, are well beyond the current capabilities of programmed systems.

As mentioned previously, Helicams are very well suited for operation from many types of moving platforms and vehicles in order to extend range. When land based vehicles are used for this purpose on public roads, local authorities should always be retained to temporarily shut down traffic and provide an escort if required in order to safely acquire the shot.

Another viable technique lies in the use of two or more pilots wherein one pilot hands off control to another in what is known as "relay mode". This effectively doubles the range of operation compared to single pilot operation and can be performed in a very seamless manner through radio communication.

At present, line of sight operation remains the predominant mode of operations for close range aerial imaging due to its inherent simplicity, flexibility and reliability. This will most certainly be augmented in the future in ways that are hard to imagine now.

For more info please visit http://www.perfectperspectivesaerial.com

Safety Considerations For Helicam Cinematography

2011-01-31T14:27:00.000-08:00

Another valid concern regarding Helicam aerial imaging is "what are the risks to persons and property?" Considering that millions of flight hours have been logged by radio controlled sport pilots over the past half century, all across the globe, and considering further that serious injuries, fatalities and significant property damage are rarely occurring events, Helicam operation is quite a safe endeavor in the hands of a professional. As a matter of comparison, professional Helicam operation has a far better safety record than ANY other form of manned aviation.

When accidents do occur with remotely piloted aircraft, in almost every case the root cause can be traced back to pilot error. Consequently, by using a pilot with decades of the right type of experience, the probability of having such an incident drops dramatically. To clarify what is "the right type of experience", it is not a pilot who can do all the latest extreme tricks and stunts but rather a pilot who has experience in precision piloting, in and around tight quarters. Stunt flying, while entertaining, is an entirely different skill set and so is of little or no value when it comes to flying a camera like it was attached to a jib.

Appropriate administrative procedures can add an additional layer of risk mitigation to the whole process. Some examples include implementation of maintenance procedures that mirror those of full-sized aircraft, redundant flight control systems and secure flight zones. Standard practice is to set up each shot similar to that of a stunt coordinator, wherein each shot is meticulously planned, rehearsed and appropriate safety precautions and emergency procedures are in place.

In the hands of a professional pilot, the level of precise control of the Helicam can be quite astonishing for the uninitiated. So much so that as a shoot progresses, reminders must be given to observe the safe minimum distance from the aircraft due to complacency that tends to set in due to this high level of observed control.

Because there has never been, nor shall there ever be, a perfect machine, a responsible Helicam operator will never fly directly over large crowds of people. Close range operations are possible however with a cast and crew strategically positioned for full visual effect but at the same time observing optimum risk mitigation techniques. Proper use of exclusion zones and secure take off/landing areas are also vital parts of this effort. Unwavering use of the techniques outlined here has allowed Perfect Perspectives to maintain a perfect safety record and 100% systems availability for the past 5 consecutive years.

For more info, please visit http://www.perfectperspectivesaerial.com

Aerial Video Demo Reel

2011-01-22T10:21:00.000-08:00

Camera Vibration or "Don't shake it like a polaroid picture"

2011-01-15T06:46:00.000-08:00

A very valid concern of filming by helicam is - how smooth can/will the resulting images be? While a blog is obviously not the best venue for an in-depth technical discussion, one cannot properly address this particular issue without at least briefly touching on some of the technical aspects. Vibration is commonly described as the periodic displacement (movement) of a body (camera in this case) from a position of rest. The vibration frequency (period) is defined as the number of cycles (times body moves from rest to each extreme and back to rest) and is often expressed in CPS or cycles per second. Amplitude is defined as the distance that is traveled during each vibration cycle. All helicopters, both large and small, generate a wide range or spectrum of vibration frequencies as a result of all the various rotating parts. To complicate matters further, unwanted camera movements can result that don't fit the standard definition of vibration as they occur randomly due to abrupt movements of the helicopter airframe and/or aerodynamic forces and wind buffeting for example. The latter type of movement can usually be reduced or eliminated by a well designed gyro-stabilized camera mount or gimbal. Okay, enough of the technical stuff already!

The challenge for the helicam builder is to design and build an airframe where all the rotating components are as perfectly aligned and balanced as humanly possible. To accomplish this is both art and science and can take years of R&D to finally achieve. Considering this, it is easy to understand why a helicam builder/pilot might want to avoid extremely high risk situations and would likely possess a particular brand of hatred for heavy-handed baggage handlers!

Each helicopter airframe produces its own unique range of vibration frequencies, displacements and amplitudes. If you built two identical airframes, side by side, the resulting vibration signatures produced by each would be similar, yet not identical. Complicating matters further, not all camera types respond to vibrations the same. 35mm film cameras are far more forgiving in this regard than video cameras for example. Conversely, SD cameras are more forgiving to vibration than HD cameras. This is due to many factors such as sensor type, image stabilization along with camera size, weight and construction. Another example is CMOS sensors do not respond well to high frequency vibrations as CCD types and can often display the unsightly "jello" effect as a result. This does not mean that they are unsuitable, it merely means a higher level of tuning is required by the builder to make them work. It should become quickly apparent that not all cameras would perform equally well on all types and sizes of helicopters. Our particular experience has shown that the smaller the helicopter, the more high frequency vibrations will be produced. This presents a very real challenge if a CMOS based camera is being used.

Gimbal stabilization can be accomplished by means of electronic gyros, mechanical gyros, inertial management units or by some combination. Most unwanted, low amplitude camera movements can be removed in post using stabilization software. Two popular examples are Smoothcam in Final Cut Pro and the Deshaker Plug-in to Virtual Dub. Use of post stabilization comes at the expense of some loss of resolution and image cropping but if used in small amounts it can be very effective. Currently this type of stabilization can not remove high frequency vibrations.

For more info please visit http://www.perfectperspectivesaerial.com

Creative Potential of Remotely Piloted Helicams

2011-01-08T07:02:00.000-08:00

Great film-making is about those infrequent, elusive moments when technical aspects (cameras, lighting, sound, editing) merge with creative aspects (compelling storytelling, great acting, engaging settings) to synergistically create something that is universally respected and admired as art. While strapping a camera to an RC helicopter with the expectation of graceful, flying imagery is certainly a technical challenge, that is not the focus of this discussion. The specific topic here is - how can this technology be used to its fullest creative potential?

A very powerful and effective use of aerials is in the creation of a "sense of place" or, in other words, an establishing shot that clearly and dramatically indicates the opening setting or, as the story progresses, a change to another location/setting. Some good examples of this would include skimming just above a glimmering ocean or lake, steadily gaining altitude to slowly reveal a tropical island or isolated lake house or some other prominent feature. This is an extremely effective means of sending the viewers mind racing with anticipation about what might follow in this new environment. Once setting is established, closer range aerials are also very effective in capturing unique and dynamic views of the characters movement and interaction within this new setting. For example, a parallel shot of a jeep driving down a curvy, cliff side road viewed from the POV of a following vehicle that suddenly veers of the cliff at a curve but then magically flies beside the insert car, out and over the gorge below. Another example is a tight overhead following shot of a convertible that slowly climbs and trails behind to reveal its steady progression down a narrow tree lined parkway.

Jib, crane and dolly shots can all be thought of as the lowest altitude "aerial shots" and are very effective also, however, in very remote areas they are often not feasible. A skilled helicam pilot can mimic many of the same movements as these camera tools while at the same time having the added benefit of increasing the range of use significantly. Use of a helicam in these situations is simply a matter of transport, either by off-road vehicle, watercraft or backpacking on foot. Once on location, a small clearing is all that is required for take off/landing. The helicopter can usually be in the air to start shooting in less than 15 minutes, making it a very productive time and money saving tool for film-making.

Effective use of close range aerials allows the film-maker to fully immerse the viewer in the world being created. In the past the use of this technology was limited only to big budget feature films but smaller, lighter cameras and more reliable aircraft designs are changing much of that. For a few thousand dollars, smaller budget productions can now incorporate these stunning camera views, adding a new level of quality to the production and captivating the audience in the process.

For more info please visit http://perfectperspectivesaerial.com

Film from full sized or remotely piloted helicopter?

2010-12-31T07:08:00.000-08:00

It should be made clear that, at present, a remotely piloted Helicam is not a direct replacement for a full-sized helicopter with a camera mount. While there can be some overlap in the operational ranges for either, to try and use one entirely in the domain of the other is neither safe nor wise. For maximum benefit the user should apply each towards its own inherent strengths. If you need a long continuous shot over a tree covered landscape, filming from full size is the best option. If you need a shot flying under a bridge or chasing a car through an abandoned building - then this is the sweet spot for a Helicam.

If budget permits however, it can be quite spectacular to blend both technologies together, combining wide, high altitude panoramic views with tighter shots like those from a birds POV.

Regarding comparative costs, hiring a Helicam with an experienced, professional crew is usually 30% to 50% less than say renting a Jet Ranger with a Tyler mount for a days shooting. I should also qualify what I consider a "professional crew" in this equation. This would be a company that carries insurance, has more than one aircraft available, has numerous examples of smooth, steady, vibration free footage and has captured this footage in a wide variety of settings and weather conditions over a period of several years.

As mentioned previously, the typical range of a Helicam is about 900 feet in the horizontal plane due to the need for the pilot to have continuous "line of sight" connection to the helicopter. This range can be increased dramatically however by using a variety of vehicles such as boats, ATV's, golf carts, cars, trucks, snowmobiles, etc. to fly from.

For more info please visit: http://perfectperspectivesaerial.com

What's the big deal about these Helicams?

2010-12-26T10:45:00.000-08:00

For aerial cinematography, think of the Helicam as a hybrid dolly and jib with an insane range of motion. Since the helicopter is not connected to the ground it can move the camera freely to any point in 3 dimensional space, providing some unique and often spectacular angles, movements and views. These aircraft are most often flown in what is commonly known as "line of sight" or LOS. For a larger, brightly colored helicopter, this range can be as much as 900 feet in the horizontal plane and 400 feet vertically when operated by a well experienced pilot. Why is the vertical distance less than the horizontal you might ask? Well this is primarily due to the policies of the FAA in the United States. It is in everyone's best interest if these unmanned aircraft do not try to occupy the same airspace, at the same time, as full size manned aircraft.

From a creative perspective, the potential of such a device quickly becomes apparent. The next question is usually one of image quality. Capturing photographs from a helicam is not a overly simple task for a competent pilot, but capturing smooth, stable film or video is an entirely different matter and requires the skill set of a true ninja/guru/master in several different arenas. This quickly explains why there is truly only a handful of companies that can consistently and reliably provide such a service. For these elite few, it is possible to provide very high quality imagery that is worthy of the big screen.

There are a variety of helicopter types and sizes used for HD aerial video and film-making. They can be powered by internal combustion engines, turbine engines and electric motors. Our personal experience has shown that turbine powered models, while smooth, are overly complex and not practical for daily use "in the trenches". Electric powered models are both smooth and quiet but have limited flight duration. Around 10 minutes flight time is typical for one set of lithium based batteries. Since aerial shots are typically short, this is usually not an issue and only a few moments are required to change batteries. Internal combustion powered models may be either methanol or gasoline powered. Once again, our personal experience has been that opposed twin cylinder engines are much smoother than single cylinder types. We have been able to obtain smooth, vibration free video from such platforms that rivals our electric powered models. A side benefit of these platforms is the ability to be continuously available for up to one hour. These platforms are also larger than current electric powered aircraft and so, are more stable, particularly in moderate winds. This is not just our opinion, it is the law. More specifically Newton's law. For HD video, the practical benefit of gas power is being able to do multiple takes, land and idle, quickly confer and make changes in direction for a given shot, take off and immediately continue filming. Over the course of a day of filming this can be a huge time savings. For 35mm filming this is less important as the cameras can only carry film loads of up to 200 feet.

For more info please visit: http://www.perfectperspectivesaerial.com