DoF: aperture calculation

I Notice this line: aperture = this.lensSize / this.fStop
But isn’t fStop = focalLength / aperture so aperture = focalLength / fStop ?

I wonder about the lensSize here

ping @sebavan

Yup you are fully right and as I remember it in most setup and any realistic one, focalLenght should be equal to lensSize. It is actually weird to have both defined separately and can not happen on a camera I guess but it provides nice artistic tricks on how it might impact the shader.