Translation guide
The Japanese word for 'photon' is 光子 (こうし). It is used in physics and everyday contexts involving light particles.
The scientific term for a quantum of light.
Standard term in physics for a photon. Used in both technical and general contexts.
Photons have no mass.
The energy of a photon is proportional to its frequency.
Alternative term for photon, literally 'light quantum'. Less common than 光子 but still used in physics.
The light quantum hypothesis was proposed by Einstein.
Referring to photons in contexts like photography, lighting, or popular science.
Even in non-specialist contexts, 光子 is the go-to word. It's understood by most educated speakers.
This camera can detect individual photons.
While 光子 is a technical term, it's widely understood in Japan due to science education. You can use it in casual talk about light or cameras without sounding overly academic.
When the number of photons is low, the image becomes dark.