Discord seems to agree that using high emissive colors with SSR seems broken in 4.15. The following gif shows a material with high emissive and it’s reflection in the starter content map. It looks like the reflection is using the old tonemapper.
Hi ninjin,
This isn’t a bug, this is just how the material properties on the floor and the SSR are interacting. For example if you have a material with pure white base color and 0 roughness it will reflect the emissive perfectly. If you have a roughness of 0.3 (this is due to the roughness lightmap mixing change in 4.14) OR your base color is darker the reflection’s emissive value gets toned down considerably.
In short this behavior is expected and users will have to adjust their workflow to these changes. If that is an issue because you have a lot of dev time in a particular project it may be best to either revert behavior where you can or stay with a previous engine version.
Regards,
Ed
Someone in the forum posted a great picture to show you are right
https://forums.unrealengine.com/attachment.php?attachmentid=130060&d=1487551085
Link to the forum post?