Not sure how long this actually has been in the source builds of UE5, but I just stumbled upon it today and was really surprised. Very happy to see this and I really hope it makes it into release.
Should be really helpful for scenes with a lot of dynamic range that are difficult to expose.
Performance cost (for this shot) was ~0.13ms on a GTX1070
Thats awesome 
Finally something, thats closer to real eyes or HDRI effects. If this works from a dark place looking at a brighter place, then it also should be good for looking from bright outside places into dark rooms/caves too.
It does! I canât post a screenshot at the moment but it works even better in that situation in my opinion.
I also find it helps a lot in smoothing out the exposure transitions so that it looks more natural as the camera moves between areas.
Im writing here because seems like there are almost no LocalExposure threads and this is the main one. I havent found much documentation on the topic if any.
The implementation of local exposure is terrible and its on by default. It causes a dark halo around any high intensity are on the screen.
A simple emissive particle:
LE:
No LE:
LE + no bloom:
No LE+no bloom:
LE (low highlight contrast so the artifact is clearly visible):
The effect becomes very clear as the emissive increases:
Its clearly visible even on the image you posted:
Local exposure is introducing artifacts on the final image on the current implementation and only creates more problems by being on by default, messing even more the contribution of each system to the final image. On top of that its a very specific solution for very specific content, it shouldnât be activated by default.
I doubt local exposure to be necessary when creating VFX/materials/animations/inspecting meshes. I dont want to see this when creating content as its only relevant for final image touches ideally and for lightning at most.
And no thatâs not how our eyes work. Its a âsolutionâ to ease the limited precision of the scene lightning.
More info on local exposure and very interesting read:
Then turn it off? Motion blur, TSR and auto-exposure are also both on by default and everybody constantly complains about them too.
Unreal has many dubious default settings. The defaults for auto-exposureâs histogram min is set way too high and pretty much guarantees the AE target will fall off of the bottom end in any remotely dark scene, meanwhile motion blur targets 30 FPS by default.
The default settings suck, thatâs software for you.
Look like an âanti-bloomâ effect/mask.
Local exposure is exposing different regions of the screen at different levels, you need to decide how it will transition between them and by default it uses a wide blur. This is fixable by simply using more conservative contrast settings and/or by adjusting the blur blend/kernel weights.
Additionally my screenshots were taken when Local Exposure was first implemented and had very few controls, it has changed a lot since then.
Also I feel like it should be obvious but if you use it without bloom, youâre going to have a bad time. The bloom is necessary to maintain some idea of what parts are âbrightâ when the overall contrast is reduced, without it the output doesnât make any sense visually.
To turn something off you need to know what to turn off. I dont see the reasoning behind an animatior/material artist having to know how Local Exposure works and what it is.
Yeah thats the point, maybe they shouldnt activate every feature by default. I dont see photoshop or visual studio having terrible default settings, dont know why unreal sould have a free pass on this matter.
No, they are two separate things. LE has nothing to do with bloom and it can and should be used even without bloom. Is a exposure adjustment, if any it can affect the threshold of bloom intensity values, but it shouldnât break bloom.
Good luck with that
