[BasilG]

No, I didn't test at infinity but at f/1.8 there was quite some field curvature anyway. Even in the theoretical event that the lens is better at infinity, the field curvature would hit astro-photographers.

 

I was going to ask about that as well. The charts at f/1.8 don't look that great - I was wondering if the image periphery would be better at longer focus distances (sometimes lenses aren't as good close up). Unfortunately in the sample image section all the wide open ones are close-ups and all the near-infinity shots are stopped down. In any case, it is more likely than not that the issues are real and apply to infinity focus too, but then I would have to wonder why others rave about the lens for astro...