Can you explain CMOS chip measurements?

[Jolyon39]

Hello,

Why is a 1/1.8 in the T5442T camera bigger than 1/3 and 1/2.8 on other cameras?

Can you explain how this measurement works and how to use it to calculate the actual area of a sensor? I like to understand the specs I am reading

 

[SouthernYankee]

it is a simple fraction
1/1.8 = .5555
1/3 = .3333
1/2.8 = .357

 

[wittaj]

They play trickery on people LOL because many will assume a 1/3 is larger than a 1/1.8 - the mind sees the larger number and makes the conclusion it is larger...

 

[tigerwillow1]

it is a simple fraction

We have a different opinion of what's simple. Snips from Video camera tube - Wikipedia

Although the video camera tube is now technologically obsolete, the size of solid-state image sensors is still expressed as the equivalent size of a camera tube. For this purpose a new term was coined and it is known as the optical format. The optical format is approximately the true diagonal of the sensor multiplied by 3/2. The result is expressed in inches and is usually (though not always) rounded to a convenient fraction - hence the approximation. For instance, a 6.4 mm × 4.8 mm(0.25 in × 0.19 in) sensor has a diagonal of 8.0 mm (0.31 in) and therefore an optical format of 8.0*3/2=12 mm (0.47 in), which is rounded to the convenient imperial fraction of 1⁄2 inch (1.3 cm).
-and-
....the optical format size bears no relationship to any physical parameter of the sensor .....

 

[Flintstone61]

That's probably clear to somebody, but not me.....My brain only sees 8 mm and says ( hey thats equivalent to my 5/16 socket). i suppose if I had a graphical representation of the sensors with the numbers next to it, that would enough for me.

 

[Flintstone61]

Sensor and pixel sizes

www.vision-doctor.com