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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?

3 Answers 3

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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

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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.

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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.

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  • Actually, image area (sensor size/total area) is far more important in terms of image noise... per pixel noise is really only relevant if you are viewing individual pixels (and not an image). Jan 16 at 1:24

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