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In an earlier blog post, we established that one of the golden rules of audio recording is achieving a good signal-to-noise ratio, and that one of the best methods for doing this is to position the microphone as close to the sound source as possible.
Camera-mounted microphones may be great for busy run-and-gun situations, but when critical dialogue is involved, they just simply cannot get close enough for a lot of applications.
This is where boompoles come into play.
Though a number of factors may influence the limitations on mic placement potential, the overall preferred method is to boom from above, or below if absolutely necessary.
Best boom positioning
Booms are a commonly used piece of sound equipment that allow you to position the mic close to your subject while staying just out of shot. Though a number of factors may influence the limitations on mic placement potential (for example, the chosen camera frame and the overall design of the set), the overall preferred method is to boom from above, or below if absolutely necessary. You should never record from the sides.
Holding the boom pole above shot ensures that the optimum pickup area of the mic is directed towards the subject's mouth, and then towards the ground - which we assume won't be generating much noise. This will give you natural-sounding dialogue, which is well-isolated from the ambience of the surroundings. In addition, the boom and mic will both be well out of the actor's way, leaving them free to roam the scene and not feel distracted by the sight of it.
If you absolutely must boom from below, ensure you switch off any noisy air conditioners or fans that will almost certainly be picked up by your microphones in an indoor setting. When listening back, you may find dialogue more bass-heavy after being captured from beneath. This is to be expected from alternate mic positions, so be prepared for a little extra work in post production to match the tone of your other dialogue to this take.
As for booming from the sides, this is not standard practice. There will naturally be a lot of ambient noise in a horizontal plane, which will sit in line with your actors and mic in this placement situation. This noise will definitely make its way into your recording, ruining your ideal signal-to-noise ratio.
Manufacturers such as ourselves understand that nobody wants to support a heavy object above their head all day long. This is why booms are generally constructed out of aluminium or carbon fibre, to keep weight minimised. The R?DE Boompole, Mini Boompole and Micro Boompole are made of the former material, while the R?DE Boompole Pro and Micro Boompole Pro are designed with the latter.
You'll find it much easier to support weight that is close to your body, rather than further away. For this reason, it is best to keep your arms close to your head, and hold them straight up. Use your front arm as the main pivot point and lock your elbow to support the majority of the boom's weight. Try to position your hand as close to the centre of the pole length as possible, to give you a better centre of gravity (though this may not be possible if the pole is fully extended).
As for your rear arm, you can use it to steer or angle the boompole as required. Grip it firmly, but not tightly, and be sure not to tap or rub it, as this will transfer unwanted sound to the mic.
If possible, hold your boom parallel to the floor and high above your head, using both arms at a similar, comfortable height. This will ensure it does not enter the corner of the camera's frame, which it could do if you were to hold the pole at a steep angle.
Of course, you don't want the tip of the mic to fall into shot either, so pay attention to any fatigue that might cause you to slowly lower it.
One great way to manage your mic height is to have visual cues marked in your head as to where the edge of frame actually is. Ask the director of camera operator to work out your lowest possible mic position prior to filming a take. Once established, take a mental note by using objects in the background as your guide. These could be the top of a building in the background, a window frame nearby or anything else you can easily see.
Proper cable management
You will also need to run an audio cable from the mic, down the length of the boom and finally to your digital audio recorder. This cable is important, and needs to be both neat and tidy - not just for aesthetic reasons, either. Good cable management will reduce any possible handling noise caused by it tapping against the boompole, and won't hinder your movements by becoming tangled.
Some booms allow you to run your cable internally through the pole, and some are even sold with pre-installed cables already inside them. These 'cabled' boompoles feature a coiled audio cable with XLR connectors at each end, perfect for quick connections to your mic and further cables to then run to your audio recording device.
A major advantage of cabled booms is the faster, easier setup time - great for high-pressure gigs such as news gathering, where you may need to react quickly to a live situation. Disadvantages, however, include a higher overall weight through the pole, no choice of audio cable type to use (you are stuck with what it comes with) and the possibility that the cable may rattle, causing unwanted handling noise.
Even before OSHA created 29 CFR 1910.269 Appendix D, "Methods of Inspecting and Testing Wood Poles," it seems likely that pole inspection was a rule of thumb for many field employees. After all, they set poles and repeatedly climbed them to handle upgrades, maintenance, wood rot and decay.
Today, given OSHA regulations and the fact that pole testing and inspections are not difficult to perform, it would also seem likely that workers would adhere to these practices. Unfortunately, some employees don't inspect a pole at all before climbing. Others believe they can easily comply with regulations by merely rapping a pole several times with a hammer prior to ascending. They have been incorrectly taught by other climbers that it's sufficient to rap a pole and listen for a hollow sound.
In the last few years, there have been several tragic events due to rotten wood poles falling or otherwise collapsing. The root cause of these events was failure to properly inspect and test the poles prior to climbing or changing tension. It is a disturbing reality to know that skilled and qualified climbers like us would forgo a basic safety procedure such as this one.
Remember that poles should be inspected not only prior to climbing, but also when working out of a manlift device or while using a digger derrick boom. If tension must be changed, consider how it will affect the pole and if the pole will be able to handle the change in tension.
Special attention also should be paid to pole inspection and testing during developmental training. Take advantage of this time to teach employees proper, safe work procedures. Additionally, make them aware of any special circumstances due to a pole's location. For example, utility workers in Florida must deal with poles set in swamp water. In the Midwest and northern areas of the U.S., poles are planted in frozen ground for several months each year.
Following is the text of 1910.269 Appendix D for use during your next tailgate. While covering this information with your crews, think about your company's guidance document regarding pole inspection and testing. Does it meet OSHA's minimum requirements? If not, this may be a good time to meet with the author of the guidance document to discuss necessary changes.
OSHA 1910.269 Appendix D: Methods of Inspecting and Testing Wood Poles
When work is to be performed on a wood pole, it is important to determine the condition of the pole before it is climbed. The weight of the employee, the weight of equipment being installed, and other working stresses (such as the removal or retensioning of conductors) can lead to the failure of a defective pole or one that is not designed to handle the additional stresses. (1) For these reasons, it is essential that an inspection and test of the condition of a wood pole be performed before it is climbed.
Footnote (1): A properly guyed pole in good condition should, at a minimum, be able to handle the weight of an employee climbing it.
If the pole is found to be unsafe to climb or to work from, it must be secured so that it does not fail while an employee is on it. The cleaning pole can be secured by a line truck boom, by ropes or guys, or by lashing a new pole alongside it. If a new one is lashed alongside the defective pole, work should be performed from the new one.
II. Inspection of Wood Poles
Wood poles should be inspected by a qualified employee for the following conditions: (2)
Footnote (2): The presence of any of these conditions is an indication that the pole may not be safe to climb or to work from. The employee performing the inspection must be qualified to make a determination as to whether or not it is safe to perform the work without taking additional precautions.
A. General Condition
The pole should be inspected for buckling at the ground line and for an unusual angle with respect to the ground. Buckling and odd angles may indicate that the pole has rotted or is broken.
The pole should be inspected for cracks. Horizontal cracks perpendicular to the grain of the wood may weaken the rescue pole. Vertical ones, although not considered to be a sign of a defective pole, can pose a hazard to the climber, and the employee should keep his or her gaffs away from them while climbing.
Hollow spots and woodpecker holes can reduce the strength of a wood pole.
D. Shell Rot and Decay
Rotting and decay are cutout hazards and are possible indications of the age and internal condition of the pole.
One large knot or several smaller ones at the same height on the pole may be evidence of a weak point on the pole.
F. Depth of Setting
Evidence of the existence of a former ground line substantially above the existing ground level may be an indication that the pole is no longer buried to a sufficient extent.
G. Soil Conditions
Soft, wet or loose soil may not support any changes of stress on the camera pole.
H. Burn Marks
Burning from transformer failures or conductor faults could damage the pole so that it cannot withstand mechanical stress changes.