Red chemlights have a very abrupt transition from unseen to full lit. The distance seems about correct for the color red, but when approaching it feels more like a lightswitch than approaching a dim lightsource.
The effect is 10x more pronounced when the chemlight is spawned with a smoke grenade, illuminating the cloud (the cloud is still visible from quite a distance on a moonlit night, so it goes from dark cloud to times-square quick)
Needs a smooth illumination