How large is 1/2 inch ?
Wheew .. Long story..
The dimensions 1", 2/3" etc where defined long before CCDs and CMOS sensors even existed. At that time tubes where used, search Wikipedia for "Vidicon" for example. The light sensitive area of a sensor is about 2/3 of that measure. A CCD or CMOS is called 1/2", when the "equivalent vidicon tube's " dimension would be 1/2", etc. Say .. simply forget about it. Regard it as a class of sensor size. not more.
Instead please use the little table below to find the sensor sizes. Or better: refer to the data sheet of the sensor you use, because even from manufacturer to Manufacturer the naming conventions (for example for 1/4") do change.
Typical sensor sizes are
| Sensor size | Width(mm) | Height(mm) | Diagonal(mm) |
| 4 Megapixel Kodak | 15.2 | 15.2 | 21.5 |
| 1" | 12.8 | 9.6 | 16 |
| 2/3" | 8.8 | 6.6 | 11 |
| 1/2" | 6.4 | 4.8 | 8 |
| 1/3" | 4.8 | 3.6 | 6 |
| 1/4" | 3.2 | 2.4 | 4 (Sony: 4.5!) |
