Sensor pixel size "pixel area" any important?

Question

Using this camera comparison tool i got pr

1. If you look at pixel pitch it shows 5.95 µm and 4.76 µm however for some reason difference they display is 25% when in reality its only 20%

2. What is "Pixel or photosite area" and should i even pay attention to this or its marketing scam (like quoting megapixels instead actual image of resolution) multiplying pixel width by pixel height to get magic number of 35.4 µm² and 22.66 µm².

3. Then when they compare difference for "pixel area" they show again 56% difference when in reality this two number differ only by 35.9%.

4. I assume pixel density also can be safely disregarded as marketing ploy?

Answer 1

That's just the nature of fractions. 5/4 (1.25) is the reciprocal of 4/5 (0.80).

1.25 - 1 = 0.25 = 25%
1 - 0.80 = 0.20 = 20%

5.95µ is 25% greater than 4.76µ

4.76µ is 20% smaller than 5.95µ

So whether the difference is 20% or 25% all depends upon which of the two numbers you select as the baseline, the larger one or the smaller one.

The numbers for area are similar:

35.4µm² divided by 22.66µm² is 1.56.
35.4 is 56% more than 22.66.

22.66 divided by 35.4 is 0.64.
2.66 is 36% less than 35.4.

It all depends on whether your baseline (1.00x) is 35.4µm² or your baseline (1.00x) is 22.66µm².

The concept should be fairly easy to grasp.

If you have 100 apples and you add 50% more, you then have 150 apples. If you subtract 50% of 150 apples, that leaves you with 75 apples, not your original 100 apples. To get back to 100 apples from 150 apples, you need to subtract 33% of the 150 apples.

This is because 100/150 is the reciprocal of 150/100.
100/150 is 0.67 (2/3).
150/100 is 1.5 (3/2).

When you add 50%, you're actually multiplying by 1.5X.

When you subtract 33%, you're actually dividing by 1.5X

Answer 2

Your math is incorrect; if you divide 4.76um by the 1.19um difference the result is 4... i.e. you would have to enlarge the NEX spec by 25% to get the D610 spec. Same with the pixel area spec.

Pixel pitch, area, and density are all just different ways of saying the same thing; pixel size.

Answer 3

Pixel area is an important factor. Larger pixel area has less noise than smaller pixel area, assuming the processing done after the sensor is the same.