Samyang 24mm F1.4 lens review: Best 24mm lens for Canon full-frame EOS users?By Kevin Carter - Wednesday March 12 2014 Lens Review
Samyang 24mm f/1.4 ED AS UMC Canon
Unlike ultra-high-speed models from the premium marques, the ultra-high speed Samyang 24mm f1.4 ED AS UMC is only $600/669. But, before you rush out to pick one up, the Samyang has no auto-focus and this Canon mount version lacks electronic data-bus contacts (unlike the manual focus Zeiss ZE model).
As a result the Samyang lacks automatic aperture control, requiring stopped down metering only. Although metering remains automatic with Canon cameras, both program and shutter-priority exposures modes aren’t available.
Besides that obvious shortcoming, the optical construction is impressive. In total it has 13 elements in 12 groups, four of which are ED glass elements to minimize chromatic aberration, while two aspheres are incorporated to reduce spherical aberration. With a 77mm filter thread and measuring 3.27 x 3.74" (83 x 95 mm) this is a big and heavy lens at over half a Kilo (580g) or 20.46 oz.
While the Samyang achieves a very high DxOMark score of 31 points, indicating that it’s a well corrected lens, the overall sharpness is a little on the low side for this type of model.
It’s particularly noticeable at full aperture where acutance was measured to be just below 60% in the center of the image field. Performance improves significantly at f2 and is very good by f2.8 but the low sharpness wide-open in the center is somewhat discouraging in a high-speed lens.
Vignetting is quite heavy as well with it reaching -2.3Ev in the extreme corners and bear in mind that no in-camera correction is available. Still it’s simple to remove in post. Low chromatic aberration is impressive in a lens like this and distortion is low as well, but it’s bordering on complex ‘moustache’ type that isn’t easy to correct manually.