Coil-based mic with moving diaphragm — tough, rejects plosives and wind noise. Workhorse for dialogue and loud sources on set.
You need a microphone that delivers on its promise — then you reach for a dynamic one. The moving coil sits in a magnetic field and reacts to air pressure fluctuations. This thing is as robust as a hammer, needs no phantom power, and forgives rough handling that a condenser microphone would immediately reject.
On set, it's your best friend for dialogue: interview situations, voice-overs, dialogue recording in noisy environments. The diaphragm has significantly lower sensitivity than a condenser — this sounds like a disadvantage, but is often an advantage. You can get closer without every breath sound becoming sound design. Plosives like P and B are less aggressive, wind noise is less annoying. That's why you see Shure SM7B or Sennheiser MD42 everywhere on film sets — proven workhorses for dialogue.
The polar pattern — usually cardioid or hypercardioid — means: you naturally isolate your source from ambient noise. Perfect when a helicopter is on location next to you. Disadvantage: The proximity effect is noticeable — your talent must therefore maintain the correct distance, otherwise the bass frequencies will become uncontrollable. You work cleaner with a pop filter. The frequency response is usually not linear — dynamic microphones color the sound, which isn't necessarily bad. Many voice actors simply sound good through them.
Practical on set: Dynamic microphones withstand moisture, dust, temperature changes — you can take them on location shoots without hesitation. No pre-tensioning, no phantom power problems. The output is low, so you need a decent preamp in the mixer or on the recorder. Don't confuse this with a lack of quality — it's simply physical reality. When working in post-production, you often have fewer room and ambient artifacts to deal with because the microphone's natural close-miking characteristics have already filtered them out. This saves time in editing.