Blurred Edges

Hi

Whenever I insert text or a shape into Motion 5 (5.2, but it happened in 5.1 as well), the edges look soft/blurry. When I zoom in to 400%, I can see that the edges are very pixellated. Shouldn't they be sharp whatever magnification? They're not imports from another application. I'm on a reasonably new iMac running Yosemite.

In the Render dropdown, resolution is dynamic and full, and quality is normal. Changing quality to best makes it very slightly better - but not sharp. I've tried ticking and unticking Flatten in Text Rendering, but nothing changes. Should text and shapes be totally sharp? Thanks.