I discovered that all the graphics in my PDF book were fuzzy if I viewed it on Leopard using Preview. Here is a screen capture of a 400 x 400 pixel area:

Using Safari to view the same page, again at 400 x 400 pixels gave me this instead:

The graphic is sharp, as I remember it on Tiger. So what is going on? Something is making Preview scale the image up and the resampling is introducing blur.

The answer is that Preview on Leopard has an extra PDF preference that is enabled by default: Respect screen DPI for scale, so even if I display at Actual Size, it's not pixel-for pixel on most screens. Once that preference is unchecked, the pages showed exactly the same way as before:

Tiger's Preview does not have this option:

And so I never have the problem on Tiger.

Update: Tiger does have the option to respect image DPI under the Images tab:

on Leopard the same option is there, and adds screen DPI as well:

But these older settings apply to images, not PDFs. And Tiger only applies image DPI, not screen DPI.

Tags: Preview, PDF, Leopard