Safety Considerations For Helicam Cinematography

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. A professional operation will be happy to provide a safety manual that details such procedures and policies. Good examples of these 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. Below is an example of Perfect Perspectives using local law enforcement to secure the flight zone for a feature film action scene.

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 7 consecutive years.

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

Aerial Video Demo Reel

While most others were struggling to fly small consumer grade cameras, Perfect Perspectives was hard at work developing rigs that could fly larger 8 - 10 lb. cameras like the HVX200 and Sony EX-1, starting way back in 2005. If we had known how difficult the struggle was going to be, we very well might have had second thoughts. However now we are very happy we didn't give up, as the many lessons learned, and equipment developed, proved to be the perfect transition to safely flying digital cinema cameras like the Red Epic and Red Scarlet with prime cine glass for motion picture aerial cinematography.

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

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

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 cycles per second (CPS). Amplitude is defined as the distance that is traveled during each vibration cycle. Velocity is another term used to measure and analyze vibration but we will leave that another discussion.

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 virtually eliminated by a well designed mechanically or electronically stabilized camera mount or gimbal. At high forward speeds, the aerodynamics of both the camera, mount and helicam airframe all come into play also. 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. The problem here is that most of the commonly produced components do not have nearly the exacting tolerances required to achieve rotational nirvana. So to accomplish this lofty goal, a combination of precise measurements, material selection, structural design, damping and vigorous static and dynamic balancing is required.  Even further, once achieved, the final design must be robust enough to hold the tight tolerances required and keep operating smoothly after numerous flying sessions. 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. Multicopters are particularly prone to rolling shutter artifacts generated by the numerous high rpm electric motors and their inherent tendency to produce either non-synchronus or sub-synchronous vibration due to the interaction between the large number of nearby rotating motors and propellers . This does not mean that they are unsuitable, it merely means a higher level of tuning is required by the designer/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. These can provide either active or passive stabilization, or some combination of both. If the camera movement is not to fast or severe, most unwanted, low amplitude camera movements can be removed in post using stabilization software. Some popular examples are Smoothcam in Final Cut Pro, Warp Stabilizer in Adobe Premiere Pro and Mercalli. For advance stabilization there are also motion trackers such as Syntheyes and the Foundry plug-in for After Effects. 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. This is another huge advantage of using ultra high definition cameras like the Red Epic for aerial filming as there is so much resolution head room. Currently this type of stabilization does still have difficulty removing high frequency vibrations, especially using wide angle lenses. This problem can be somewhat corrected however by removing lens distortion in software.

The most exciting advancement in the area of camera stabilization is direct drive gimbals. Advances with this technology are currently moving at near light speed. Very soon you will be able to shoot close range aerials, full size aerials and ground level steady cam type shots, all with the same mount.

The bottom line is however, the less vibration the helicopter produces - and the camera sensor sees, the better! This is why Perfect Perspectives uses only the most advanced vibration monitoring/dynamic balancing equipment available to ensure smooth footage. This is not referring to the vibration app on the iphone or vibration logs off of flybarless controllers here, but rather industrial grade, precision FFT vibration spectrum analyzers, multichannel accelerometers and laser alignment instrumentation.

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

Creative Potential of Remotely Piloted Helicams

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