Hello Armin,
I am having the same troubles within the carousel theme.
As Ana says, it is a difference between safari and firefox.
I activated "Never show resized versions of your images"
But still.. Safari is blurry, firefox is sharp.
http://buero146.ch/nathalie-pellon/
We do have some smaller images uploaded. But this specific one is new and definitely in bigger size.
And since we want to optimize the other projects as well, we'd be curious to see it working in advance.
Do you know what it could be?
Or what we could do?
Thanks a lot in advance!
Maike