Samyang 16mm F2 ED AS UMC CS

General Image Quality

When looking at the Samyang 16mm F2.0 from an image quality standpoint, it is comprabable to the 15mm Limited, a lens renowned for its sharpness and aesthetic renditioning. The 16mm can serve as a quality landscape, architecture, or close-up wide-angle lens. Before we proceed to our technical analysis of the lens's performance, some of the more practical qualities of the lens are outlined below.

Field of View

For a landscape lens on APS-C format, this lens hits the sweet spot in terms of coverage and quality. With 83.1 degrees of diagonal coverage, this lens is able to do a commendable job of detail rendering while not losing distant objects like a wider angle is apt to do if framed improperly.

The closest K-mount relative to this lens, the 15mm Limited, does an equally impressive job of balancing detail and field of view, albeit at close to double the price and two full stops slower. What you gain is 3 more degrees of diagonal field of view, an ultra-compact form factor, as well as an autofocusing system.

15mm vs 16mm field of view comparison (16mm in red)

Detail

As wide-angle, manual focus lens, the Samyang 16mm does an incredible job of rendering details. Compared to the 15mm Limited, it does a tremendous job capturing a slightly smaller field of view. Below are two sample images of the same scene, taken at F4.0 on a Pentax K-3. The image taken by the 15mm Limited has been resampled to match the field of view from the Samyang 16mm F2.0. As is apparent in the image comparison below, there is a negligible loss in detail from lens to lens.

Color and Contrast

The Samyang 16mm F2.0 produces similar color rendition and contrast to the 15mm Limited. Using a small levels adjustment in post-processing can deliver good results. There is a slight discrepancy between the two in their color rendition but it is very minimal. The Samyang casts a slightly greener hue, while the Pentax casts a redder hue.

As seen below, the Samyang 16mm F2.0 delivers similar contrast and color when compared to the 15mm Limited.

Metering and Exposure

At large apertures, the 16mm tends to underexpose the entire frame by up to two-thirds a stop, with the corners following off up to a full stop. At smaller apertures on a Pentax K-3, pictures tended to be underexposed, but the effect showed up more sporadically than the intense vignetting when used wide open.

Lens Corrections and EXIF Data

The Samyang 16mm F2.0 utilizes the Pentax KA mount, which only transmits aperture information to the camera.  The latest autofocus K-mount lenes transmit a number of other parameters, including focal length. This means that the aperture settings are able to be controlled in body, but past that, no lens information is exchanged. At the start-up menu, you therefore will need to input the focal length in order to optimize in-camera Shake Reduction. This entry will be saved in the EXIF data with no lens make or model attached to it.

This lens features an aperture ring with the “A” setting, as well as manual dialing of the ring. Aperture information will not be saved in the EXIF data if the aperture ring is away from "A" on digital cameras, and manual stop-down metering will need to be performed.

Pentax offers in-camera distortion, aberration, and vignetting fixes only for modern (DA, D FA, and FA limited) genuine lenses. Manual corrections using post-processing software will need to be done with this Samyang lens.