Letters starts to pixelate then I when zoom in.

[JustinR]

So I allways though that fonts are vectors, but when I really zoom in to my text it starts to pixelate a lot... So can I turn on sth to prevent this?

[dv8_fx]

It will always do that. It's how PS displays fonts. Don't zoom in close. View it in the actual viewing size.

You can select a desired look in the anti-aliasing settings in the text menu bar.

Hope this helps