What is camera image size?

The specifications of C mount camera always include “image size” and “image sensor size”.

In addition, this size is the value needed to calculate the field of view (when selecting the lens).

(To calculation of field of view, please refer to “f value of lens”.)


You can also calculate the size of one pixel.

For example: The image sensor of 1 / 2.5 inch of 1.3 million pixels (1280 X 1024) is:

Horizontal  5.6 mm / 1280 pixels = 0.0044 mm / dot

Vertical    4.2 mm / 1024 pixels = 0.0041 mm / dot.


Incidentally, the lens side specification also has a description of “1/2 inch camera “ correspondence.

In this case, It doesn’t means “the len is compatible with only 1/2 inch camera”. In other way, it means “can be used with cameras of 1/2 inch or less”.

As described above, the field of vision will change.


The sensor image size of 1/2-inch, 1 / 2.5-inch, 1/3-inch mainly used by our company as follows.


Do you notice that strange thing?

For example: With 1/2-inch of sensor, the diagonal is 8 mm.

The 1/2 inch is 8 mm when it is 12.7 mm.

This is due to the special circumstances of the image sensor to use as the criteria of the imaging tube.