Would I be right in thinking that a senor 1/1.8” is about double the size of a 1/2.8" making a camera with a 1/1.8” 4Megapixel senor about the same as a 1/2.8" 2Megapixel when it comes to light sensitivity?
I have a HDW5231R-ZE which is a 2MP with a 1/2.8” sensor size. I also have a HDW5442R-ZE which is a 4MP with a 1/1.8” sensor. The 5442 is a newer model but both day and night look better than the 5231.
The sensor sizes are not to be taken literally. They are approximations after an adjustment is made to normalize them to old-tech video camera tubes. Comparing two advertised values might give a good approximate comparison to each other, but to get exact sizes you have to find out what make/model sensor a camera uses and go to its manufacturer data sheet. Not being a political or social issue, I tend to trust the wikipedia info or this. A key statement is:
The optical format is approximately the diagonal length of the sensor multiplied by 3/2. The result is expressed in inches and is usually (but not always) rounded to a convenient fraction.
And it's not only a matter of size. The sensitivity of later sensors will be improved. Along with the supporting image processing hardware beyond the sensor itself.
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