What you see is my Snow Leopard (OS X 10.6) desktop, in 960×600 HiDPI.
After reading about HiDPI modes in OS X Lion and how it handles HiDPI, I wanted to check it out for myself. My 17-inch MacBook Pro has a pixel format of 1920×1200. So what I could do is halve the pixels horizontally and vertically to see what HiDPI would look like.
I used Quartz Debug, set the User Interface Resolution to 2.0, and effectively doubled the resolution on my MacBook Pro. And when I say resolution, I am referring to pixel density, as in ppi. In OS X Lion the setting would be 960×600 HiDPI.
HiDPI used to be a tricky concept, but thanks to the iPhone 4 it is easier to understand and to explain. The iPhone 4 can be thought of as running in HiDPI. On iPhones prior to the iPhone 4, the 3.5-inch LCD had a pixel format of 480×320 (landscape). The LCD was upgraded to 960×640 in the iPhone 4. Everything stayed the same size, except they were all much much sharper. That’s what HiDPI offers on the Mac.
Without HiDPI, setting my MacBook Pro to 960×600 would result in icons and text that are very fuzzy. In 960×600 HiDPI everything, except for web text (I’ll get to this later), is crisp.
It seems parts of Snow Leopard is already tuned for HiDPI. Look at how sharp the menu items are compared to web text from DisplayBlog. Icons are razor sharp: the red, yellow, green buttons, the Safari icon, the Trash icon, etc. But if you look at the top right corner the Spotlight search icon, AirPort icon, and the clock text are not HiDPI ready: they “shrank” by one-half both horizontally and vertically. Same goes for the mouse pointer, the bottom-right window resize icon, and contents within the Finder window.
There is one other problem, and this is big: text on the web look horrible. Web text look identical to non-HiDPI 960×600 on my MacBook Pro. I’ve googled to find out how to make text on the web take advantage of HiDPI monitor settings without success. Even text on John Gruber’s excellent Daring Fireball isn’t HiDPI aware. Does anyone know of a way to take advantage of HiDPI for text on the web?
I’m sure Apple does. I’m certain because Apple makes web text look great on the iPhone 4. Sooner than later, Apple will need to apply that knowhow to web text on OS X. I’ve seen a glimpse of HiDPI on my MacBook Pro and the visual clarity is amazing. I look forward to iPhone 4-level clarity on my Mac in the not-so-distant future.