What makes the Nikkor AF-S 50mm F1.8g lens so sharp?

How do we get so sharp and crisp images especially through this lens?

I know this is a weird question but this question was stuck in my mind throughout the day: P

Prime lenses are generally sharper than zoom lenses, due to the manufacturing process of having to have movable lens elements.

Prime lenses are always sharper than zoom lenses. There are fewer elements in them when compared to zoom lenses and the fewer the number of air to glass interfaces there are (up to a point) the less degradation of the image and the light passes through each one.

Slower lenses of the same focal length tend to be sharper lenses because there's less bending of the light at the edges of the widest part of the lens

Here is what is inside a typcial Nikkor 50 mm f/1.8 lens: 7 glass elements in 6 groups

The 50 mm f/1.4 lens: 8 glass elements in 7 groups (needed for the extra 2/3rds stop aperture)

The 24-70 mm f/2.8: 15 lens elements and 11 groups

The 70-200 mm f/2.8 lens: 21 glass elements in 16 groups

One of the sharpest 50 mm lenses on the planet is the Leica 50 mm f/2: 6 lens elements in 4 groups.

As you can see, the culprit is all the air to glass interfaces that make lenses more complicated and less sharp than the ideal. Combining certain lens elements in to groups reduces the air to glass interface by one, slightly increasing the sharpness of the lens across the width of the projected image at the film plane.

Of course the type glass used in lenses is also a factor as is the lens coating used by the maker. You will see the use of ED and FL lens elements in the more exotic lens designs to further reduce internal lens flare and ghosting. The newest lens coating is Nikon's Nano Crystal variant.