---
title: "Gamma"
url: https://postproduction.studio/en/glossary/gamma
language: en
description: "Gamma is the non-linear relationship between input signal values and output luminance in image encoding, originally derived from the response curve of c..."
updated: 2026-10-25
---

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# Gamma

Gamma is the non-linear relationship between input signal values and output luminance in image encoding, originally derived from the response curve of cathode-ray tube displays and retained in modern digital workflows for perceptual efficiency. The human visual system perceives brightness logarithmically — small steps in dark areas are very visible while large steps in bright areas are barely noticed — so allocating more code values to shadows via a gamma curve produces images that look smooth at modest bit depths (8 or 10 bits). The Rec.709 broadcast standard specifies a camera-side OETF roughly equivalent to gamma 1/2.2 and a display-side EOTF of gamma 2.4 (formalized as BT.1886). DCI-P3 theatrical uses gamma 2.6 for the darker projection environment. sRGB uses a piecewise function approximating gamma 2.2 with a linear toe in shadows. Inside grading sessions, you choose a working space whose gamma matches the intent: log curves (ARRI Log C, Sony S-Log3, RED Log3G10) are gamma-like but stretch a much wider dynamic range; linear-light spaces (ACEScg, scene-linear EXR) have no gamma at all and are used for VFX compositing where mathematical operations like blur and additive compositing require linear data. Confusing gamma with the underlying transfer function or with the working space causes the most common color-pipeline bugs. Reference: ITU-R BT.1886 (display gamma) and the IEC 61966-2-1 sRGB specification.

Color Science, ImageColorist, DITCapture, Color Grading

## Related terms

[Logarithmic (Log) Curve](https://postproduction.studio/en/glossary/logarithmic-log-curve)[EOTF (Electro-Optical Transfer Function)](https://postproduction.studio/en/glossary/eotf-electro-optical-transfer-function)[Luminance](https://postproduction.studio/en/glossary/luminance)

Each extra bit doubles the number of code values per channel. 16-bit floats are essential for VFX compositing math.

## Articles covering this term

* [Ambient Light and Perception: Gamma, PQ, HLG, and Dolby Vision IQ

  How ambient light affects perceived contrast. A complete guide to Gamma, HDR PQ, HLG, Dolby Vision IQ, and their implications for post-production.](https://postproduction.studio/en/image/ambient-light-gamma-hdr)
* [Color Spaces: Rec.709, Rec.2020, P3, sRGB

  Deep dive into color spaces, gamuts, primaries, white points, and color science. Master Rec.709, DCI-P3, Rec.2020, and ACES for professional workflows.](https://postproduction.studio/en/image/color-spaces)
* [Primary and secondary grading: methodology

  Comprehensive guide to primary secondary grading methodology. Master global balances, contrast curves, HSL qualifiers, selective masks, and shot matching.](https://postproduction.studio/en/image/primary-secondary-grading)
* [LUTs and CDL: managing color decisions

  Complete guide to LUT and CDL workflows: 1D/3D LUTs, ASC CDL parameters, technical vs creative transforms, on-set monitoring, archiving and color management best practices.](https://postproduction.studio/en/image/luts-cdl)
* [The grading suite: equipment and environment

  Detailed guide to grading suite equipment and environment. Explore calibration, control panels, workstations, monitoring chain, storage, and lighting.](https://postproduction.studio/en/image/grading-suite)
* [Reference monitors: OLED, LCD, HDR

  Technical guide to reference monitoring displays. OLED, LCD, HDR evaluation, calibration standards, viewing environments, and professional display technologies.](https://postproduction.studio/en/tools/monitoring-displays)