S-Log3 (Sony Log 3) is a logarithmic gamma curve used for recording video footage. It is not a color space in itself, but rather a method of encoding luminance information in the image to maximize dynamic range and provide greater flexibility in post-production grading. S-Log3 is commonly used in combination with a color gamut, such as S-Gamut3 or S-Gamut3.Cine, to form a complete picture profile on Sony cameras. The gamma curve describes how tonal values (brightness levels) are recorded, while the color gamut defines the range of colors that can be captured. So when talking about S-Log3, it's essential to understand that it deals primarily with the luminance aspect of an image, not the color aspect.