Sound-dampening rigid case around the camera body — kills motor noise and mechanical rattle for dialogue recording. Non-negotiable for location sync sound.
Blimp
On set, it quickly becomes clear why the blimp is indispensable: the camera itself is noisy. The shutter clicks, the motor hums, the gears grind — all frequencies that the microphone mercilessly picks up when recording synchronized sound. The blimp is nothing more than a custom-made soundproof housing made of foam and often lead fabric, which envelops the entire camera and drastically reduces these noises. Without it, dialogue recording with modern digital cameras is often simply not feasible.
The construction is proven and simple: multi-layered acoustic insulation materials — foam, sometimes coated with melamine — surround the housing. The blimp sits on rubber mounts and opens towards the lens turret, allowing lenses to be changed or follow focus to be attached. Size and weight are considerable — a standard blimp weighs 8 to 15 kg, depending on the camera. This means heavy support systems, shoulder rigs, or cranes are necessary. Setup takes time, and in practice, an additional focus puller with a gear system is often used because the blimp makes direct lens operation impossible.
A reduction of 12 to 18 dB in damping effectiveness is normal — not absolute silence, but enough to keep the original sound usable. This is particularly relevant for cameras with noisy shutters (classic film roll-shutter cameras) or for high-speed recordings where the motor frequency climbs into the critical frequency range of speech. Digital SLRs and cinema cameras benefit to varying degrees — a RED or Alexa often needs a blimp, while a Sony FX30 might only need one in very sensitive sound situations.
Practicality: The blimp is requested before shooting days because specialists mount and calibrate it. There are custom blimps for almost every camera model, and some rental houses build their own. Time for setup is reserved in the shooting schedule — blimps are not accessories for spontaneity. Those who don't have a blimp available or find its weight too prohibitive resort to alternatives like isolation boxes (for static shots) or — as a last resort — to sound editors who work with VST noise reduction later. But that's a patch-up job; on set, a good blimp is worth its weight in gold.