The Samyang is the second third party lens (non Oly non Pana lens) after the Voigtländer Nokton 25mm f/0.95. I am not a fisheye fan but I know Samyang can do very good lenses. I do hope they will announce more m43 lenses soon! Meanwhile let’s see how this lens performs! Lenstip (Click here) tested the brand new Samyang 7.5mm. And there are only good news! The lens has a “sensational image quality in the center of the frame…excellent image quality on the edge of the frame, including the maximum relative aperture“. There is only ver low chromatic aberration, almost no astigmatism, no coma and well balanced vignetting. The only “Cons” for the polish website is the lack of depth of field scale. You can find plenty of image samples after their conclusion text.
UPDATE: There is a hands-on video on the facebook page of ThePhoBlographer.