How does Preview calculate to display PDF when I select View / Actual Size? I switched from a Samsung 2493HM to a Crossover 2720MDP monitor. In testing, I opened PDF in OS X Preview (I am on Mountain Lion) and found that by default, the display size is very small, like this: 



Notice that I chose View / Actual Size (command-0). Normally the Preview tries to render the page to sized like a piece of paper. 

On this new monitor, a page renders to a size around 2 credit cards. 

Where can I find the controls to get OS X to understand display pitch correctly and therefore allows Preview to view actual size correctly?
There is a setting in Preview > Preferences, in the Images tab which might be relevant: