The other day I was working on some blog posts, and when I pulled up an image in Preview to edit it, I noticed something odd. It looked like the Preview window was transparent, and that I was seeing a window through it. I thought nothing of it until a few minutes later when I closed a number of open windows on my new 27" iMac and noticed that a faint "echo" of those windows was visible on my desktop photo. I realized I was seeing some image persistence.
This is nothing new; back in the days of PCs with cathode-ray tube monitors, it was quite common to see the C: prompt burned into some screens, visible even when the monitor was turned off! But this was a bit of a surprise, since I hadn't experienced image p
