So the higher the fill factor, the more sensitive a sensor is to light. To reiterate what we learned, how sensitive a sensor is to light directly affects the ability of a camera to capture images in low light situations without having to use either high ISO levels (possible noise) or long exposure times (possible loss of sharpness).

A (perhaps obvious) but interesting note is that the non-photosensitive area (i.e. the underlying metal/wire/circuitry) remains the same size! But when we increase the pixel resolution, we are therefore increasing non-photosensitive area and decreasing the total photodiode area. We cannot simply increase the number of pixels to get a more detailed reading!

The pixel fill factor is actually the photodiode area divided by the total area. In this slide, from my understanding, it goes down from left to right, since the non-photosensitive are for each square is at the same size. Therefore, it increases the non-photosensitive area, and pixel fill factor decreases. Correct me if I am wrong