Today Apple launches the iPad mini to an eager world. It's a terrific device (don't take my word for it: read our for full testing and analysis) but one question hung over the launch: why doesn't it have a Retina display, and after a sequence of Retina iOS launches, will the reduction in screen resolution be painfully obvious?

Mark Hattersley has the full low-down on the , but for those who'd like to see a quick comparison of the iPad mini with a Retina display, we've put together head-to-heads on iBooks and Safari.

The iPad 3 is top; the iPad mini is below. Bear in mind that this is seriously cropped in to highlight any minor differences between the two devices. But at this sort of magnification you can easily see the lower resolution of the iPad mini's non-Retina display.

Now, you won't be looking as closely as that. And the difference is only this obvious when you look at the two side by side, or swap straight from one to the other. But there's a noticeably greater degree of pixellation on the iPad mini.