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.
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.
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.