One of the more important characteristics of these primes is the bokeh they produce. For those of you that are unfamiliar with the term bokeh it refers to the character of the out of focus area and highlights in an image. Using a different apertures will change the bokeh in an image based on the number and type of aperture blades in the lens and the amount of depth of field in the image.

A prime lens at its maximum aperture will have circular out of focus highlights and a relatively shallow depth of field. While a lens at middle aperture like F/5.6 or F/8 will have out of focus highlight the mirror the shape of the aperture blades and more depth of field.

Nikon AF NIKKOR 50mm f/1.8D

Nikon AF Nikkor 50mm F/1.4D

Nikon AF-S NIKKOR 50mm f/1.8G

What kind of bokeh you like will depend a lot your personal preference. But in general softer out of focus areas and more circular highlights are preferable hard out of focus shapes and hexagonal highlights.

All three of the lenses we’re comparing here have seven bladed apertures. The 1.4D has an advantage thanks to its large maximum aperture which allows it to throw more of the image out of focus. But the 1.8G has rounded aperture blades so that even when you stop it down from its maximum aperture its out of focus highlights will still have a semi-circular appearance. This is opposed to the hexagonal highlight appearance you’ll see with the 1.8D and 1.4D when they’re stopped down.

In the photos on the left you can clearly see the differences in the aperture blades between these three lenses.

For this comparison I’m using a landscape of the inter-bay area of Seattle looking into downtown. These shots were all taken at ISO 100 using the lenses maximum aperture from a tripod using a wireless trigger to ensure consistency.

Specifically we’ll be comparing the quality of the background bokeh in these images. In the first set all of these lenses were set to their minimum focus distance.

Nikon AF-S NIKKOR 50mm f/1.8G

Nikon AF Nikkor 50mm F/1.4D

Nikon AF NIKKOR 50mm f/1.8D

There are two things that immediately standout: the 1.4D produces largest out of focus highlights and the 1.8D has the smallest highlights. 1.8G has the smoothest bokeh while the 1.8D has the most character. The 1.4D and the 1.8G actually have very similar bokeh, but the highlights on the 1.4D have a thin green outline around them that isn’t present in the photo from the 1.8G.

The bokeh of the 1.8D is arguably the least attractive looking of all three of these lenses. It’s spheres have both hard outlines and morph into half spheres as they get closer to the edge of the frame. On the other hand some people are into that. Maybe you’re one of them; I know, that at times, I am.

To consider the sharpness of these lens I’m going to defer to DXOMark’s lab testing for basic insights and then I’ll be supplementing that with additional field testing. My field testing will be broken down into two categories: a maximum aperture portrait and a landscape shot at F/8.