Overexposed License Plates with LED Headlights

[Deleted member 37895]

vb


The concept that "there could be frames of video where it blows out but plenty of frames where you will get the plate" also applies to cars directly in front of you. Sure, when your own headlights are blasting plates in front of you they will get blown out on video but reflections are actually based on the "angle of incidence". The reflective paint on the plates changes the equation somewhat but doesn't eliminate the laws of physics.

View attachment 36772

I know we would all like to capture clear images of the brightly illuminated license plates of the cars directly in front of us and that's a worthy goal but if you stop to think about it, when accidents happen that's often not the angle the car is coming at us from unless they've slammed on their brakes.

License plates are painted with retroreflective paint so no matter the angle of incidence they will be extremely bright. Being offset is better because they're being hit by less bright light from your headlights

 

[Dashmellow]

License plates are painted with retroreflective paint so no matter the angle of incidence they will be extremely bright. Being offset is better because they're being hit by less bright light from your headlights

Well yeah, that's been said and was also illustrated in the graphic I posted. Whether your headlights are bouncing off the plates directly in front of you or the car's headlights in the next lane are bouncing off the plates directly in front of him the camera will fail to capture the plate if the dynamic range exceeds the sensors capability. Reflective paint will still scatter the light. So will metallic car paint for that matter. Being offset from headlight reflections may be slightly less of a problem than when a car is directly in front of you but it's not like the problem goes away.

 

[kinglerch]

After doing some experimenting with this unit, I found that the EV does help reflective license plates, street signs, etc at least somewhat. You don't realize just how reflective these things are until you see them with a camera. For me the sweet spot is -2/3. At a EV of 0 there is no question that you can see more in the dark but the light areas bloom and anything reflective at all will go full on white, where on the -2/3 setting, it looks very normal to my eye and the things that reflect and go white are only with direct headlights in the dark.

Again, I thank Street Guardian for offering as many configurations options like this, but of course I always wish there were more (mode where the unit does not display anything when powering up, auto daylight savings time)

 

[kamkar]

Yeah if only cameras worked as good as our eyes, or rather as good as our brain think our eyes are.
Human vision are somewhat of a crap shoot, this are one of the things magicians prey on to fool us.
The human only see a tiny little dot in the middle of our field of view really good, our brain think all we see are just as good, but its just a lot of extrapolation going on.