En N-Log Specification Document Version 1.0.
N-Log Specification Document Version History Version Date 1.0.0 September 1st, 2018 Contents 1. Introduction.............................................................................3 2. Curve Characteristics .............................................................4 3. Gamut and White Point .........................................................
N-Log Specification Document 1. Introduction This document describes N-Log curve and colorimetric information. N-Log is designed to permit full use of sensor dynamic range in a professional movie workflow. The curve characteristics of N-Log balance shadows and highlights and are optimized for 10-bit movie recording.
N-Log Specification Document 2. Curve Characteristics The following figure shows N-Log curve characteristics. 1024 896 10-bit code value 768 640 512 384 256 128 0 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 Stops The function from N-Log to reflectance is as follows. if (x < 452) y = (x/650)^3 −0.0075 else y = exp[(x−619)/150] end x is the N-Log 10-bit code value. y is reflectance. (“y = 0.18” is equivalent to Stop 0.) The function from reflectance to N-Log is as follows. if (y < 0.
N-Log Specification Document 3. Gamut and White Point The table below shows the gamut and white point for N-Log. CIE xy chromaticity White point Red primary Green primary Blue primary x 0.3127 0.708 0.170 0.131 y 0.3290 0.292 0.797 0.046 The white point of N-Log is D65. The gamut for N-Log is same as the wide color gamut known as “ITU-R BT.2020”.
