How to handle saturation at night due to headlights?

D

davidm

n3wb
Feb 4, 2016
16
0
Hi I have a DS-2CD2432F-IW. I want to be able to see people through the windshield of cars as they approach but at night the headlights pretty much make this impossible as when the lights shine even somewhat in the direction of the camera everything is "whited out" due to the headlights. Unfortunately I can't just turn off the night setting either so this doesn't happen. What other settings should I be playing with here to try to make it so I can make out as much as possible?

Thank you!
 
davidm said:
Hi I have a DS-2CD2432F-IW. I want to be able to see people through the windshield of cars as they approach but at night the headlights pretty much make this impossible as when the lights shine even somewhat in the direction of the camera everything is "whited out" due to the headlights. Unfortunately I can't just turn off the night setting either so this doesn't happen. What other settings should I be playing with here to try to make it so I can make out as much as possible?

Thank you!
Click to expand...
Try the WDR setting...
 
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davidm said:
Hi I have a DS-2CD2432F-IW. I want to be able to see people through the windshield of cars as they approach but at night the headlights pretty much make this impossible as when the lights shine even somewhat in the direction of the camera everything is "whited out" due to the headlights. Unfortunately I can't just turn off the night setting either so this doesn't happen. What other settings should I be playing with here to try to make it so I can make out as much as possible?

Thank you!
Click to expand...

Forget about seeing through windshields at night. It won't be bright enough unless they have their interior lights on. Faster shutter speed is typically the key to eliminating headlight washout, but it makes everything else way too dark unless you have some serious lighting.
 
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Kawboy12R said:
It isn't magic but it helps. Give it a shot.
Click to expand...

I definitely will but ugh, I got rid of the Windows 10 laptop I had so now I'll have to figure out a way to change the settings on it again. It probably means having to use Virtualbox or something. So annoying to have to install a second OS just to change some settings on a video camera. I wish these companies would quit requiring proprietary plugins needlessly. The next camera I buy will NOT have this junk.
 
It doesn't look like BLC will do it as it is too small of an area to have an effect. It only allows me to specify a general area like center, top, bottom,etc and that doesn't work well enough. If I could custom draw say a box it would probably work.

Let's look at this a different way maybe. Forget the application and let us just say I want to change the settings so they make out the most details possible when headlights are directly shining on the camera. Basically let us say I want to see into the headlights and get as much detail as possible without the image being saturated by bright light. How would I do this? From what I understand it is like WDR but in reverse. Instead of overexposing the bright images and making the darker areas brighter, I want to make the brighter areas darker so that more detail can be seen there.

I was reading around about some doing similar things to try to read license plates and from what I understand lowering the exposure time might help. Also possibly reducing gain. Any other ideas?

Right now to test I have the camera in a dark room with a bright CFL light pointed directly at it. I guess I am going to mess with it until I can make out as much detail as possible on the bulb and the enclosure even with it in full brightness and pointed directly at the camera about 15-20 feet away.

Kawboy12R said:
What, everybody doesn't love Microsoft and run Windows on everything??
Click to expand...

LOL well I use zoneminder for one on the server and Linux on the Desktop. Much safer in my opinion. Little malware worries. Almost everything (both as in freedom and cost) is free.
 
even tho the hiks require a plugin to view the video, you can configure them from most any browser/platform
 
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It seems the main settings to mess with are "exposure time" and gain.

In my test without trying to tune anything else 1/2000 exposure with 0 gain actually did the best with the light test in that it came closest to being able to make out the details of the bright light itself and the surrounding enclosure as about like the human eye can. No matter what I tried though (even going up to 1/100,000 exposure with zero gain) I couldn't get it to make out the details on the brightest part of the bulb itself as my human eyes can a bit. Of course at this exposure time objects in the background other than the light are pretty much pitch black or dark gray shadows at best.

It was an interesting exercise to see how changing the settings make a difference and pretty educational at least.

For being able to see objects around headlights it looks like (using 0 gain) an exposure time somewhere between 1/500 to 1/1000 will work best. Possibly as low as 1/250. Of course without the bright lights (headlights) and in the areas outside of that area you'll get barely anything.

Note all these tests were with the IR LED OFF but night vision settings otherwise.

It will be interesting to see what works best in live tests tonight or tomorrow night. :)


pozzello said:
even tho the hiks require a plugin to view the video, you can configure them from most any browser/platform
Click to expand...

It mostly works but for example the settings for "image" do not stick. It generally saves only when there is a SAVE button present. For settings without it, it seems to autosave using the required plugin.
 
Well it looks like 1/120 exposure time with 50 gain is about as good as it gets for my particular application. Just thought I would share for anyone else needing to do something similar. If 1/120 is too dark also try 1/60 or adjust gain. Typically exposure time is quite a bit higher for night settings and that will cause problems with bright lights. The sacrifice in doing this as mentioned above is that everything else is much darker so it is only for special situations.

Now I just wish I had something better than a 2.8mm for this. Oh well. :/
 
Davidm,

You are asking this camera to do something it really not meant to do. handle headlights without washout, see through windshield, identify occupant of vehicle. Not going to happen with this model from their value series line. Just not going to happen sorry to be the messenger of bad news.
 
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