[avandonk]

It is simple folks just look up Sampling Theorem and Nyquist Theorem. Shannons Theorem also helps.

This only works mathematically if your optic has inherently better resolution than your sensor. It has nothing to do with fractional pixel movements but a redundancy in sampling. It is immaterial how big the dither steps are as long as they are random.

Your resolution is not your pixel size but actually twice this at best. At forty five degrees to your pixel separation it is actually worse by a factor of nearly root two.

So to make it simple with nine micron pixels at an image scale of 3.1 seconds of arc. A single image has at best 6.2 seconds of arc resolution. With dithering and upsizing this can come back to about 4.4 seconds of arc resolution at best. To display this you need at least 2.2 seconds of arc per pixel! I think if you do the simple calculation that a 6000x6000 pixel image from my system is a tad over 2 seconds of arc per pixel.

Trying for more resolution with smaller pixels say 6 micron will at best give you without dithering about the same. Meanwhile you have given up well depth and dynamic range.

It is all about balance of the variables.

Another factor is that resolution is limited by diffraction and is purely dependant on the F ratio of the optic. It is not dependant on focal length and/or aperture solely.

By the way to try and see a difference in 'resolution' of eight bit jpg's is a futile exercise.

You have to compare the original 200MB 16bit tiffs for that.

Bert