1/2.3-inch type Lenses
6.17 x 4.55 mm image area · 1 interactive lens diagram
Small-sensor compact cameras, superzooms, action cameras, and early Pentax Q bodies | 6.17 x 4.55 mm sensor with a 7.67 mm diagonal
The 1/2.3-inch type format is much smaller than its name suggests. The inch-type label comes from older video tube naming conventions, not from the sensor's physical diagonal; in this catalog it maps to a 6.17 x 4.55 mm active area. That tiny frame made it common in compact cameras and long-range superzooms, where manufacturers could pair very short focal lengths with lenses that delivered dramatic equivalent zoom ranges in a small body.
Optically, this format pushes lens design toward miniature scale. Image circles are small, focal lengths are extremely short, and depth of field is deep even at relatively bright f-numbers. The tradeoff is that diffraction, sensor pixel density, manufacturing tolerances, and alignment become more visible limits. When catalog entries use this format, they show how photographic lens formulas behave when the capture area is closer to compact-camera territory than interchangeable-lens still systems.