Samyang 10mm F2.8 ED AS NCS CS

Distortion

Like many other ultra-wide lenses, the Samyang 10mm F2.8 exhibits a moderate amount of barrel distortion, which means that lines that are straight in real line curve toward the center of the image.  The "brick wall" test photo below illustrates the degree of the distortion:

In Adobe Photoshop, we needed to apply a manual geometric distortion correction of approximately +5.5 in order to straighten the lines between the bricks.  For a lens as wide as the 10mm, this is actually quite good.

What's more interesting is that when shooting natural scenery or interiors, the uncorrected image often ends up looking more appealing than the corrected version.  Three examples follow.

Verdict

The 10mm's barrel distortion is only easy to spot in photos containing parallel lines and repeating man-made patterns, such as the window photo on the previous page, or a fence or wall.  However, for landscapes, close-ups, and interior photography, the distortion is almost always going to be a non-issue, if not a boon.

It is easy to correct the distortion using desktop software; our only regret is that this cannot be done in-camera with this particular lens.  Remember that when you correct distortion, the extremes of the scene are cut away.