SAMYANG 10mm f/2.8 ED AS NCS CS

A real rarity, this is an ultra-wide-angle prime lens for APS-C format cameras

Ultra-wide prime lenses for APS-C cameras are rare, and Canon doesn’t make one at all. The best option is this 10mm ‘Crop Sensor’ lens from Samyang, which combines a short 10mm focal length with a wide f/2.8 aperture rating. Not just a manual focus lens, this one has no internal electronics. So, you can’t set the aperture from the camera and can basically only shoot in Aperture Priority or Manual – adjusting the aperture with the control ring. The camera viewfinder’s focus confirmation lamp is also disabled.

Thankfully, the focus ring has a long rotational travel and marked focus distance scale. Depth of field markers are also on hand, but only for apertures of f/2.8, f/4 and f/5.6. Still, manual focusing is easy for most landscape shooting, and you can always resort to magnified Live View.

Build quality feels solid and robust, but the lens lacks any weather-seals. Glass includes two aspherical elements and one ED (Extra-low Dispersion) element, plus nano-structure coatings. The construction includes an integral hood, which precludes the fitment of filters, as there’s no attachment thread.

Performance

Centre-sharpness is good throughout the aperture range, with the sweet spot being at f/5.6. Levels of sharpness are consistent across the whole frame, with little drop-off, even in the extreme corners. Colour fringing is controlled, but barrel distortion is a little worse than average.