I have a D80 with 18-200mm Lens and just bought a SB-400 speedlight. I’m using the flash on the camera but am unsure on what settings to keep the camera at. I have been using Auto and it seems to be working fine, I even changed to S priority and used a shutter speed of 125 and with the flash on it seems to work fine. However, I just want to know the correct way to expose shots when using the flash as when looking in the viewfinder the exposure meter is reading way under as it thinks the shot will be under exposed.