I'm an ametuer to photography world. I know that DSLR cameras physically alter the aperture of the lens to allow or disallow light and alter depth of field as well.

iPhone 16 camera configuration for 3 cameras are 24mm f/1.78, 13mm f/2.2 and 120mm f/2.8.

They say the iPhones don't have variable aperture function so the aperture won't phyically open or close.

So I assume iPhone camera have fixed apertures - 1.78, 2.2 and 2.8. I believe with these apertures you would get shallow depth of field by default.

My question is how come iPhones take F8 pictures as the camera itself can't provide long depth of field because the apertures are fixed to max 2.8? I would like to know computationally how it does that.