Introduction

The Samyang 21mm f/1.4 ED AS UMC CS is a fast manual focus lens for mirrorless cameras with APS-C or smaller sized sensors, offering a focal length equivalent to 31.5mm on 1.5x crop APS-C sensor, 34mm on 1.6x crop sensor (Canon M) or 42mm lens on 2x crop Micro Four Thirds sensor. The Samyang 21mm f/1.4 is constructed of eight glass elements in seven optical groups, including one extra low dispersion lens (ED) and three glass aspherical lenses (ASP), with multi-layered and anti-reflexive UMC coatings to help prevent ghosting and flare. The Samyang 21mm f/1.4 ED AS UMC CS is priced at £269 / $499.

Ease of Use

The Samyang 21mm f/1.4 ED AS UMC CS is quite compact, measuring about 6.7cm in length and weighing in at 275-290g, depending upon the mount. We tested it on a Sony A6000 APS-C camera, which felt well-balanced in use.

The Samyang 21mm f/1.4 ED AS UMC lens mounted on a Sony A6000

The Samyang 21mm f/1.4 ED AS UMC lens mounted on a Sony A6000

The Samyang 21mm f/1.4 ED AS UMC lens mounted on a Sony A6000

The Samyang 21mm f/1.4 ED AS UMC lens alongside a Sony A6000

Build quality is very good for such an affordable lens. The Samyang 21mm f/1.4 ED AS UMC CS feels very solid in your hand, even if the outer barrel and the filter thread appear to be made from plastic.

Side of the Samyang 21mm f/1.4 ED AS UMC lens

Front of the Samyang 21mm f/1.4 ED AS UMC lens

Rear of the Samyang 21mm f/1.4 ED AS UMC lens

The focusing ring is generously wide and has a ridged, rubberised grip band. As this is a manual focus lens only, there's a distance scale that runs from the closest distance of 28cm to infinity, but sadly no depth of field scale.

At the base of the lens is an aperture ring, adjustable in 1/2 stop (0.5 EV) intervals, which has a definite clicking action. An uncoupled (de-clicked) manual aperture version of the lens (the Samyang 21mm T1.5 ED AS UMC CS Cine) is also available if your main interest is shooting movies rather than stills.

Front of the Samyang 21mm f/1.4 ED AS UMC lens

Rear of the Samyang 21mm f/1.4 ED AS UMC lens

The lens is generously supplied with a detachable petal shaped lens hood, lens caps and soft lens bag. The filter size is 58mm. Focusing is performed internally so the Samyang 21mm f/1.4 ED AS UMC CS doesn't change length and the filter thread doesn't rotate, good news for filter users.

The Samyang 21mm f/1.4 ED AS UMC lens, in-hand

The Samyang 21mm f/1.4 ED AS UMC lens with the supplied lens hood fitted

Note that the Samyang 21mm f/1.4 ED AS UMC CS lens doesn't have any electronic contacts for transferring exposure information to the camera body, so the EXIF data won't include anything about the lens, such as the focal length and aperture that were used for each shot.

Chromatic Aberrations

Chromatic aberrations, typically seen as purple or blue fringes along contrasty edges, are something of a problem with this lens, largely because the camera body isn't performing any automatic corrections due to the lack of electronic contacts on the lens - the examples below show the worst-case scenario.

Light Fall-off

With the lens wide open at f/1.4, you can see some very noticeable light fall-off in the corners. Stopping down helps, although to completely get rid of this phenomenon, you will need to use an f-stop of f/5.6 or smaller.

Macro

The Samyang 21mm f/1.4 ED AS UMC CS is not a macro lens. The close-focus point is at 28cm from the film/sensor plane. The following example illustrates how close you can get to the subject, in this case a CompactFlash card.

Close-up performance

Bokeh

Bokeh is a word used for the out-of-focus areas of a photograph, and is usually described in qualitative terms, such as smooth / creamy / harsh etc. One of the main reasons to buy a fast lens is to be able to isolate the subject from the background, which is normally very hard to do with a wide-angle lens. Samyang was apparently very much aware of this requirement, as they employed an iris diaphragm with 9 rounded blades for a pleasing rendering of the out-of-focus highlights. Based on what we have seen, we can say that they largely succeeded. Below you'll find some examples, but you are also encouraged to check out our sample images.

Sharpness

In order to show you how sharp this lens is, we are providing 100% crops on the following page.