12 comparison tools
Sound & light
Loudness, brightness, frequency and wavelength, against sounds and lights you know.
- Brightness An illuminance against moonlight, a lit room, an office and direct sunlight.
- Bulb brightness A lumen figure against the old incandescent wattages everyone still thinks in.
- Camera exposure Shutter speeds, apertures and ISO on the stops scale they all share.
- Colour temperature A kelvin figure against candlelight, bulbs, daylight and a clear blue sky.
- Echo distance A delay converted into distance, using the speed of sound.
- Frequency range A frequency against human hearing, musical notes and the animals that hear beyond us.
- How hot is that? A temperature from absolute zero to the centre of a star, on one logarithmic scale.
- How loud is that? A decibel level against whispers, traffic, concerts, jet engines and the damage thresholds.
- Light wavelength A wavelength against the visible spectrum and the invisible bands either side.
- Noise at home Household noise levels against the thresholds for annoyance and sleep disruption.
- Note frequencies A frequency against the notes of equal temperament, octave by octave.
- Safe listening time The exposure time before hearing damage begins, at each sound level.