The test in Optyczne.pl:

" „I’ll honestly admit that I’m dubbing my eyes out of amazement till now, Because the curve looks really great. Most of all the object lens behaves very well in the blue band. The transmission surpasses 90% for 420 nm already, what happens very rarely. It is even better when we go to the centre of the visible range. For 500 nm the transmission reaches even 98%! What does it mean? The conclusion is very important as this value tells us that on one border of the centres the cheap, produced in Korea Samyang, loses 0,2% of light! Cosmic technology has arrived under the thatch. Something, what was not so long ago available only at the best for a lot of money..."

"One of the biggest advantages of Samyang is the way of transverse chromatic aberration correction. On the edge of both DX and FX matrix it is very small.

“Another disadvantage which won't be considered as an obstacle is distortion. Both on a full frame and DX it is not noticeable as it amounts to -0.33% and -0.11%. Taking into consideration that measuring errors amount to around 0.1%, the distortion is practically near zero.”

The test on Canon-Board forum:

- I think - and take to comparison Canon 85mm L II.. In the centre this model is definetly better. Samyang on the average, but this "average"maintains evenly on the ENTIRE display frame. The 85 L in the corners is so-so, but Samyang is clearly better....I don’t believe it. I run the test 3 times in a row – sharpness of course on LiveView – is still the same. Let me remind You that these are 100% crops from a full frame jpg (21 MPX). And? It’s shocking. If someone put there ANY AF, I would sell the L and saved 7k zł The new 85 L is now about 8900zł. This is astonishing! While conducting the Zeiss test there was no astonishment – aberration occured on a full hole there -here there is no such thing. I’ll write it in capital letters: The glass for 900zł vignetts less, aberrates less, works better against the light and it has a better sharpness in the corners of the frame than the glass 10 times more expensive.”