# Effect Composer Gamma Output Difference

**URL:** <https://discourse.threejs.org/t/effect-composer-gamma-output-difference/12039>\
**Category:** Questions\
**Tags:** post-processing, gamma\
**Created:** [January 12, 2020, 10:19pm UTC](https://discourse.threejs.org/t/effect-composer-gamma-output-difference/12039 "2020-01-12T22:19:24Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![DolphinIQ](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.threejs.org/dolphiniq/32/3510_2.png) [@DolphinIQ](https://discourse.threejs.org/u/DolphinIQ)\
**Post date:** [January 14, 2020, 12:13pm UTC](https://discourse.threejs.org/t/effect-composer-gamma-output-difference/12039/7 "2020-01-14T12:13:14Z")

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> [@looeee](#):
>
> **Some more considerations for post processing:**
> 
> - some passes need to be in linear space (before tone-mapping) and some need to be done after. Some can be done before or after but you’ll get different results (e.g. vignette).
> - Outline effect looks like it has tone mapping built in (probably incorrect?)
> - `AdaptiveToneMappingPass` and `ToneMapShader` have filmic tonemapping built in. We should change that to ACESFilmic.
> 
> Before tone mappings: bloom, lensflare etc  
> Then, in order: 1. tonemapping 2. gamma correction  
> After tone mapping: brightness, contrast, FXAA, SMAA, color correction  
> Order not important (or, choose what looks best to you): DOF, vignette, film grain etc.
> 
> I’m not sure where where exposure comes into this - either before all passes, or just before tone mapping?

Wow, thanks @looeee! This is some great, useful info I haven’t seen anywhere else 👀

> [@looeee](#):
>
> - It would be great if a final tone mapping pass was automatic when using the EffectComposer. Even better, combine color correction/tonemapping/brightness/contrast as the final pass (again, that’s what Unreal does I think).

That would be the dream scenario 😍  
but removing built in color corrections inside some passes would be a great start. Its simple to just add `toneMapping`, `gamma` etc at the end of the composer chain, but what complicates things is selfish passes with corrections built in, that break the chain.  
Would Takahirox’s PR fix that issue?

Also Im not sure I got an answer for this, but why would `renderPass` and `renderPass + copyPass` give different colorspace renders? (or different results at all?) This actually seems to happen with 1 or more passes added after `renderPass`, regardless of the pass type (but a basic `copyPass` shows it clearly).  
And why does it suddenly stop respecting the `renderer.outputEncoding`? 🤔 🤨

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