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The griz photometric system was developed in the 1970s/1980s for use with electronic sensors, eventually CCDs. Other names are the Gunn photometric system, the Thuan-Gunn photometric system, and the Oke-Gunn photometric system, for some of its principal developers. "griz" indicates the letter names of the passbands:
| passband indicator | centered on | |
| g | 475 nm | green |
| r | 622 nm | red |
| i | 763 nm | near infrared |
| z | 905 nm | infrared |
The passbands are cited in various ways, such as Gunn-i. The ugriz photometric system used by Sloan Digital Sky Survey (SDSS) is something of a follow-on but their corresponding passbands are not identical.