I've got 3 Korg tuners (all different models) and was surprised to discover how much variation there was between them. I checked the calibration with a signal generator and discovered one was off by just over 5 cents, another by about 3, and 1 is within 1.5 cents. I thought I'd mention this as a reminder that "All tuners are NOT created equal," even when they are made by the same company. Whenever you are recording, make sure everyone uses the same tuner. A tech can check the calibration of your tuner and let you know how accurate it is. Most people can't hear less than about a 3 cent variance so if your tuner is within 1-2 cents of accurate you should be fairly safe in using it. As others have said many times, for accuracy you can't beat a strobe.