Optical material

Technical Optical Data

Area sensor CCD & CMOS imager size (unit: mm)

Below are typical sizes. Please note that there are different sizes even if they are the same inch.

How to find the imaging range and focal length of a CCTV lens

Example: If an object at a distance of 10 m is photographed using a 1/2" camera with a lens with a focal length (f) of 25 mm, what is the height (Y) of the object? 10mの距離にある物体を1/2″カメラにて焦点距離(f)25mmレンズを使用して撮像した場合、その物体の高さ(Y)はいくつになるか？

10mの距離にある物体を1/2″カメラにて焦点距離(f)25mmレンズを使用して撮像した場合、その物体の高さ(Y)はいくつになるか？

Example: If a 3m high object at a distance of 10m is imaged with a 1/2" camera, what is the focal length (f) of the lens? 10mの距離にある高さ3mの物体を1/2″カメラにて撮像する場合、そのレンズの焦点距離(f)はいくつになるか？

10mの距離にある高さ3mの物体を1/2″カメラにて撮像する場合、そのレンズの焦点距離(f)はいくつになるか？

How to obtain monitor magnification and overall magnification

monitor magnification: Monitor inches x 25.4 (1 inch) ÷ camera diagonal image size
Overall magnification: Monitor Magnification x Optical Magnification

Front converter lens and rear converter lens

This lens cannot be used alone, but is used in combination with the main lens. The front converter lens is attached to the front of the main lens, and the rear converter lens is attached to the C mount behind the main lens. At that time, the optical properties change as follows.

M.: Main lens magnification
NAMore: Main lens front numerical aperture
NA': Rear numerical aperture of main lens
MI: Front converter lens magnification
M2: Rear converter lens magnification
MT: total magnification
NAT: Front total aperture
NA'T: Rear total numerical aperture

Line sensor image size (unit: mm)

Imaging relational expression

f: Focal length
FF: front focus
FF': back focus
H.: front principal point
H': rear principal point
P.: physical point
P': image point
S.: Distance from front principal point to object point
S': Distance from back principal point to image point
X: Distance from front focus to object point
X': Distance from back principal point to image point
M.: magnification
R.: resolution
d: depth of field
R': Image sensor resolution (2 pixels)
λ: wavelength
NAMore: Object side numerical aperture
NA': Image side numerical aperture

An inverted real image is obtained when M is negative, and an erected virtual image is obtained when M is positive.
General lenses have a negative M, while front converter lenses and rear converter lenses have a positive M.
A lens with a positive M cannot be used alone, and must be used in combination with a lens with a negative M.
When using a CCTV lens with a magnification of M, the lens extension amount isX'becomes.