deept teevrata

prakaashamiti mein mein, prakaash srot se disha vishesh mein, ikaai thos kon mein, nikalne waali tarang-dairghya-bhaarit shakti ko deept teevrata (lyumins intensiti) kehte hain. yeh prakaasheeya sootr (luminosity function) par aadhaarit hai, jo ki ek maanaveeya aaainkh ki sanvedanasheelata ka ek maanakeekrut pratiroop hai.

iski SI ikaai kaindila (cd) hai.