Wide angle prime lenses compared

The classic 28mm prime lens is a natural part of any lens lineup. Most kit zoom lenses include the 28mm equivalent in the wide end, but you can also get prime (non-zoom) lenses with the same field of view.

Below are three such lenses, for three different interchangeable lens systems. How do they compare?

From left to right: Sigma 19mm f/2.8 (old style) mounted to a Sony NEX-3N, Lumix G 14mm f/2.5 mounted to a Lumix GM1, and Nikon 1 10mm f/2.8 mounted to a Nikon 1 V3 with a user optional EVF.

Lens	Sigma 19mm f/2.8	Lumix G 14mm f/2.5	Nikon 1 10mm f/2.8
Announced	Jan 10th, 2012	Sept 21st, 2010	Sept 21st, 2011
System crop factor	1.5	2	2.7
Equivalent focal length	29mm	28mm	27mm
Maximum aperture	f/2.8	f/2.5	f/2.8
Equivalent max aperture, in terms of DoF	f/4.2	f/5	f/7.6
Weight	140g	55g	77g
Diameter	61mm	56mm	56mm
Length	46mm	21mm	22mm
Filter thread	46mm	46mm	40.5mm
Minimum focus	0.20m	0.18m	0.20m
Lens elements/groups	8/6	6/5	6/5
Hood included	Yes	No	No
Focus ring	Yes	Yes	No

The lenses are laid out here:

Prime lens overview

Prime lenses are lenses without a zoom function. They have a constant focal length, and a constant angle of view. When the Micro Four Thirds system was introduced, the very first prime lenses were the Olympus 17mm f/2.8 and the Lumix G 20mm f/1.7. While the Olympus prime lens was generally disliked for the limited maximum aperture, the Lumix lens was an instant classic with the brighter aperture and the perceived very good optical qualities.

Since that time, a lot of prime lenses for the M4/3 system have been introduced. In this article, I present an overview of these lenses.

First, here is an illustration which presents the lenses in terms of the focal length (the X axis) and the aperture (the Y axis). In the picture, the lenses are plotted as dots, where the size illustrate their relative price, and the colour the brand:

In the rest of the article, I illustrate what the focal length and aperture means, before going into details about the individual lenses.