I have their darkest tints all around on my car. It is not a daily driver and I rarely drive it at night so I cant really answer the question about light loss. I just removed my tail light covers and had them install the tints on the tails. the covers were much darker I think.
Just as stated above it will reduce your light visibility by almost 50%. I had the darkest headlight and fog light tint for awhile. And I have hids. Recently wanted to change the look so I peeled and replaced with clear film just to protect them. Put it this way I liked the look of the dark tint but the difference of the light for night time driving I won't go back.
i have the smoked color tint on headlights and green film on fogs with led bulbs can still see fine like was said before i think its a 12% loss....didnt care for that you still see some of the light think mine were cut wrong couldnt get them to cover all the light for the life of me..gonna redo with vht when i take lamps apart for halos and will do the fogs as well..the green looks like xmas with the red stripes
I got the "Blue Optic" and when the lights are on, you can not tell that they have anything on them but, when off and during the day you can see that they are not just clear just love the effect on my SRT Plum Crazy!!