Originally posted by dcmsox2004 from what i've read, shoot the sky (no clouds preferably) at f22, or f16, look at the pics....
If you don't have a clear sky (or it's night), shoot a plain white surface, keeping it out of focus (eg a fridge door, from close up, focused to infinity). Together with the f16-22, it also helps to set a low ISO, so you don't have noise complicating your assessment. It doesn't matter if that results in a long exposure - anything on the sensor will be clearly visible. It also helps to scan the pics at 100% magnification, as the small spots are often not clear in full view. Many of us found the spots dead centre, looking like a "string of pearls" - dark spots with a distinct halo round them. My second K-5 has two very small ones bottom right, but they are insignificant for normal shooting, and I've decided to live with them. Good luck, and enjoy your K-5 - its a wonderful camera.