Iliah: All the taking lens aberrations play against increased sensor densities too. Shake and motion blur are more prominent.
These words misleadingly imply that higher-megapixel sensor images are going to "show more blur and shake" than lower-megapixel sensor images
when all images are shown at the same display size .
If shake and motion blur cause a line that "should" be imaged by a perfect optical system at, say, 100 micrometers width at the sensor, to instead spread out to a fuzzy-at-the-edges 200 micrometer width line, then sensors with pixels at 10 micrometer spacing are going to render the line with about the same 100-micrometer-added-blurred-width-due-to-motion as a sensor with 5 micrometer width pixels.
Your inconsistent interest in precise discourse tells me that you are going to respond to this (if at all) with vague and dismissive words, rather than get out your numbers and explain how the 5 micrometer pixel pitch sensor would show significantly more of the 100-micrometer line motion blur, in a given display size image, than the 10 micrometer pitch sensor.
Or perhaps you meant us to understand that lens aberrations "playing" against increased sensor densities merely meant us to understand that pixel densities "affect" rendering of lens aberrations, without you meaning to imply that the higher densities "negatively affect" the rendering? Or perhaps when you said blur "is more prominent", you
meant us to understand that blurs are more prominent when a 24 megapixel image is viewed is viewed at twice the height and width of a 6 megapixel image (as is easy to do when looking at side-by-side images each "displayed at 1:1/100% crop size)?
My point is not to argue with you for argument's sake, but rather to discourage publicity of the notion that higher-resolution sensors doom your motion-blurred pictures to look blurrier at a given display size.
It is further carelessly broad to write that "all lens aberrations", when displayed at a given print size, are more problematically rendered by higher resolution sensors. Yes, for example
some lens flaws such as lateral chromatic aberration (color fringes) would be rendered more precisely (hence in many cases more problematically) by a higher resolution sensor.
But certainly lens aberrations that lead to plain old fuzzy image rendering (such as curvature of field in a otherwise perfectly corrected lens) will not produce a softer look with a higher resolution sensor. Nor of course will gross geometric distortion be rendered differently by a higher-resolution sensor.
In our example above, suppose the blur described was caused not by camera or subject motion, but by lens curvature of field. Once again the 10-micrometer pitch sensor will show the 200 micrometer width line as a line with at least traces of its width varying between 200 and 210 micrometers. The 5-micrometer pitch sensor will not be showing any traces of the line wider than 205 micrometers, hardly an example of the smaller-pixel sensor showing a fine detail as
more bloated by the lens aberration.
My point is not that any given higher-resolution sensor will be overall better than any lower-resolution sensor, or that anyone should want higher or lower megapixels. There are so many factors that could make one or the other sensor better for a given user. But it is unreasonably confusing to people considering what kind of sensor they might want, to write that at a given display size, higher-resolution sensors inherently exaggerate
every lens problem, or to write that they exaggerate motion blur.
You pointed out plenty of other interesting and important reasons why it gets harder and harder to make a great sensor with ever-smaller pixels. But you also threw a couple of smaller-pixel problems into your laundry list that didn't belong there.
