An exposure compensation of +1 will make the image 1 stop brighter (AKA twice as much) compared to how the camera would otherwise expose the image.
To quickly correct any errors, you should take advantage of exposure compensation. This is usually represented by a +/- symbol on the camera. An exposure compensation of +1 will make the image 1 stop brighter (AKA twice as much) compared to how the camera would otherwise expose the image. Likewise, an exposure compensation of -1 makes the image 1 stop darker (half as bright).