Can you explain CMOS chip measurements?

Jolyon39

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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
 

wittaj

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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

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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 .....
 
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