>>4026109Your question is not well worded enough to give a precise answer.
For me it helps to think of it in terms of cine resolution formats:
Your eyes cannot see anything above 4k or around 12 megapixels. That's why 4k is pretty much the standard export format for cine today. Saying that, there are cine cameras that shoot above 4k, i.g. 6k, 8k with Red and 12k with Black Magic. The extra resolution is used in post to crop, make image adjustments, and to obtain a sharper final output image when you downsize to a 4k output format.
As for lenses. Most high end cine lenses outperform your sensor resolution via their high number of resolved line pairs.
Assuming you do not want to crop or work with your image in post, the A7s's FF 12.2mp 4288 x 2848 resolution sensor gives you enough resolution for an excellent photo. Although in reality most people will want more image data to work with in post, which is where a 18mp sensor is probably the baseline resolution that you want for digital photography.
More resolution doesn't really mean more sharpness by itself, it just means more pixels. What really matters is how sharp your lens is. An extremely sharp lens on a 12mp sensor can outperform a softer lens on a 24mp sensor.
With a decent lens, the advantage of a super high resolution sensor e.g. 50mp or 100mp is that you can then output your image as 4k and amplify your image quality (sharpness) when you downsize for output.
