# Lumen reflections rendering latency / refresh rate in real time ??

**URL:** <https://forums.unrealengine.com/t/lumen-reflections-rendering-latency-refresh-rate-in-real-time/1203578>\
**Category:** Rendering\
**Tags:** unreal-engine, Global-Illumination, Lumen\
**Created:** [June 19, 2023, 12:46am UTC](https://forums.unrealengine.com/t/lumen-reflections-rendering-latency-refresh-rate-in-real-time/1203578 "2023-06-19T00:46:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![WBDeSportVaL](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/wbdesportval/32/718785_2.png) [@WBDeSportVaL](https://forums.unrealengine.com/u/WBDeSportVaL)\
**Post date:** [June 19, 2023, 12:46am UTC](https://forums.unrealengine.com/t/lumen-reflections-rendering-latency-refresh-rate-in-real-time/1203578/1 "2023-06-19T00:46:17Z")

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Hello,  
Here’s my problem. I have integrated a led screen on my stage, but I have a rendering problem with lumen, the reflections don’t load quickly enough and when there are strobes or fast videos the reflections are super slow (video attached). In scalability i set Shadows, GI & Reflection to “High”.  
The video signal comes from a Blackmagic capture card, I have the same problem with NDI…

Maybe Lumen isn’t made for this idk ? I’m still new to unreal

Do you have any ideas?

Video : [Lumen reflections problem - YouTube](https://youtu.be/jAhmycCF0Iw)

PC Config :  
I9 10900X  
RTX 4070  
32GB RAM

Many thanks

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<div class="post-metadata">

**Author:** ![Arkiras](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/arkiras/32/1008648_2.png) [@Arkiras](https://forums.unrealengine.com/u/Arkiras)\
**Post date:** [June 19, 2023, 1:47am UTC](https://forums.unrealengine.com/t/lumen-reflections-rendering-latency-refresh-rate-in-real-time/1203578/2 "2023-06-19T01:47:04Z")

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> [@WBDeSportVaL](#):
>
> Maybe Lumen isn’t made for this

It’s not. I’d go as far as to say it is fundamentally incompatible with this type of use case.

You can try increasing the Lumen update speed in the post process volume… but honestly… I highly doubt it’s possible to make it update fast enough to accommodate a strobe light.