Picture tuning suggestions

[steve0805]

We have just put in a couple of cameras to monitor the entrance to our neighborhood. Our LP capture is operating well but I'm having trouble getting our overview camera to capture acceptable images at night. Our only goal for this camera is to be able to identify the color and model of the cars entering/leaving. Because the camera is located at the top of a T intersection, it is largely blinded by headlights until the cars start to turn. We have some ambient light from a street lamp just to the left of the capture area.

It seems like because of the bright headlights/taillights, the rest of the car image is underexposed so the color is hard to identify. And when cars are on the right side of the street, the lower ambient light appears to be making them almost too noisy to identify.

The camera is a IPC-Color4K-T with shutter set to 20ms, gain to 60, noise reduction to 70 and HLC to 55.

I'd appreciate any tips or ideas--I'm just getting started with this stuff and am not exactly which parameters to focus on for this scene

 

[wittaj]

Drop the Gain and NR way down. That is all contributing to the problem. Try with HLC off.

In terms of getting the most out of the camera, here is my "standard" post that many use as a start for dialing in day and night that helps get the clean captures and help the camera recognize people and cars.

Start with:

H264
12,000 bitrate
CBR
15FPS
15 iframes

Every field of view is different, but I have found you need contrast to usually be 6-8 higher than the brightness number at night.

We want the ability to freeze frame capture a clean image from the video at night, and that is only done with a shutter of 1/60 or faster. At night, default/auto may be on 1/12s shutter or worse to make the image bright.

In my opinion, shutter (exposure) and gain are the two most important parameters and then base the others off of it. Shutter is more important than FPS. It is the shutter speed that prevents motion blur, not FPS. 15 FPS is more than enough for surveillance cameras as we are not producing Hollywood movies. Match iframes to FPS. 15FPS is all that is usually needed.

Many people do not realize there is manual shutter that lets you adjust shutter and gain and a shutter priority that only lets you adjust shutter speed but not gain. The higher the gain, the bigger the noise and see-through ghosting start to appear because the noise is amplified. Most people select shutter priority and run a faster shutter than they should because it is likely being done at 100 gain, so it is actually defeating their purpose of a faster shutter.

Go into shutter settings and change to manual shutter and start with custom shutter as ms and change to 0-8.3ms and gain 0-50 (night) and 0-4ms exposure and 0-30 gain (day)for starters. Auto could have a shutter speed of 100ms or more with a gain at 100 and shutter priority could result in gain up at 100 which will contribute to significant ghosting and that blinding white you will get from the infrared or white light.

Now what you will notice immediately at night is that your image gets A LOT darker. That faster the shutter, the more light that is needed. But it is a balance. The nice bright night static image results in Casper blur and ghost during motion LOL. What do we want, a nice static image or a clean image when there is motion introduced to the scene?

In the daytime, if it is still too bright, then drop the 4ms down to 3ms then 2ms, etc. You have to play with it for your field of view.

Then at night, if it is too dark, then start adding ms to the time. Go to 10ms, 12ms, etc. until you find what you feel is acceptable as an image. Then have someone walk around and see if you can get a clean shot. Try not to go above 16.67ms (but certainly not above 30ms) as that tends to be the point where blur starts to occur. Conversely, if it is still bright, then drop down in time to get a faster shutter.

You can also adjust brightness and contrast to improve the image. But try not to go above 70 for anything and try to have contrast be at least 7-10 digits higher than brightness.

You can also add some gain to brighten the image - but the higher the gain, the more ghosting you get. Some cameras can go to 70 or so before it is an issue and some can't go over 50.

But adjusting those two settings will have the biggest impact. The next one is noise reduction. Want to keep that as low as possible. Depending on the amount of light you have, you might be able to get down to 40 or so at night (again camera dependent) and 20-30 during the day, but take it as low as you can before it gets too noisy. Again this one is a balance as well. Too smooth and no noise can result in soft images and contribute to blur.

Do not use backlight features until you have exhausted every other parameter setting. And if you do have to use backlight, take it down as low as possible.

After every setting adjustment, have someone walk around outside and see if you can freeze-frame to get a clean image. If not, keep changing until you do. Clean motion pictures are what we are after, not a clean static image.

 

[bigredfish]

Are you running the onboard white LEDs? I assume not

I would first raise the angle of the camera a bit. It may help pick up light. You don't have much without running the LEDs

I have a similar scene maybe a bit longer shot, low light from a weak streetlight. Its tough to get enough light on close in objects. You see samples of lighted scenes in the distance 150-500ft away and think Wow! But any camera can get good images of bright lights in the distance when close in detail isn't needed.
My settings attached (4K-X bullet)

Try these or even up to 8ms without HLC. The exposure itself will darken the scene and damp the lights a bit







View attachment Home_ch1_20250102060705_20250102060716.mp4
View attachment Home_ch1_20250101203758_20250101203810.mp4

 

[Mike A.]

Primary issue - need more light. Even just a little however you might do it would help things a lot. You can play with settings forever and you'll still not really get there otherwise.

Could you move the cam to a location where you may have more? e.g., If it were down near the driveway in the background, that would be better.

 

[adamg]

What are the camera encoding settings? Screenshot of that page. bitrate, resolution, codec...

 

[steve0805]

What are the camera encoding settings? Screenshot of that page. bitrate, resolution, codec...

Here's the encoding settings:

 

[steve0805]

Primary issue - need more light. Even just a little however you might do it would help things a lot. You can play with settings forever and you'll still not really get there otherwise.

Could you move the cam to a location where you may have more? e.g., If it were down near the driveway in the background, that would be better.

We had limited places where could install the camera and backhaul the signal to the NVR. Our primary goal was to capture plates, which is working well. So now we just need to get as much as we can from the overview. We'd be happy with just car color and model--don't need a lot of detail.

I had started from wittaj's guidelines, but there just wasn't enough light without longer exposure/higher gain. And even at those settings everything but headlights and tailights were black without HLC. I haven't used the exposure compensation parameter--Could that substitute for HLC?

(I think) there are two issues: the total amount of light and getting the camera to choose a decent exposure/aperture when the scene is mixed between very bright areas (which are not interesting to us) and the dimmer areas that are. Tonight I think I will separate those issue ie 1) work on the image of a stationary car with lights turned off 2) work on the image of a stationary car with lights turned on and 3) work on the image of a moving car with lights turned on.

 

[Mike A.]

You could try it but exposure compensation won't do the same thing as HLC. And, at least as I've found it, it seems to do absolutely nothing on some of my cams when using manual exposure. I don't recall how that goes on the 4K-T.

Yes, to the last point especially when you have near complete darkness in the foreground and light in the distance. As @bigredfish said above, well-lit static things in the distance will look great. Up closer where dark, not so much.

Are you running the on-board LEDs? Off-cam lights are better if you can do it. No AC power there for a light? I've not looked for it but assume that there are POE lights that you could find. Just a little light goes a long way with these cams. I use Hue LED landscape spots in my otherwise pitch black yard that are 15 watts at max level and they light up things beautifully for a 4K-X even when turned way down to only ~20% of that. You'd easily get car color with that much light.

 

[steve0805]

You could try it but exposure compensation won't do the same thing as HLC. And, at least as I've found it, it seems to do absolutely nothing on some of my cams when using manual exposure. I don't recall how that goes on the 4K-T.

Yes, to the last point especially when you have near complete darkness in the foreground and light in the distance. As @bigredfish said above, well-lit static things in the distance will look great. Up closer where dark, not so much.

Are you running the on-board LEDs? Off-cam lights are better if you can do it. No AC power there for a light? I've not looked for it but assume that there are POE lights that you could find. Just a little light goes a long way with these cams. I use Hue LED landscape spots in my otherwise pitch black yard that are 15 watts at max level and they light up things beautifully for a 4K-X even when turned way down to only ~20% of that. You'd easily get car color with that much light.

Yeah--hoping to avoid extra lighting for aesthetic reasons but may have to go there. But I'm still not sure how much of the issue is ambient light. As I mentioned, the left side of the image is almost under a street light and the right side is about about 40 ft away. The scene is far from pitch black. It will be interesting to see what happens when I remove the headlight and motion variables....

 

[bigredfish]

Still havent answered whether you are running the onboard LED lights? It matters

 

[steve0805]

Still havent answered whether you are running the onboard LED lights? It matters

Nope they are off. Our previous Flock camera was disabled twice by bad guys, so we want to keep this installation more obscure. If we have to add light, we would use some kind of external lighting.

 

[Mike A.]

I wouldn't have guessed that you had any other light there. Curious to see what it looks like without car lights.

 

[steve0805]

I wouldn't have guessed that you had any other light there. Curious to see what it looks like without car lights.

Yes. There's a good chance this situation is just because I don't know what I'm doing...

 

[Mike A.]

Decent chance not. Many of these cams adjust the image to brighter lights in ways that you can't completely control no matter what you do with settings.

 

[Ookie]

What is the negative of turning backlight off?

I have a lot of security lighting. One 40,000 lumen stadium lights on each side of the house, barn, etc. With all the light available, it seems that I do better with HLC.

 

[adamg]

You might have to give us remote access so we can try various settings.

 

[steve0805]

Update: I ran the tests that I mentioned earlier. As most of you pointed out, there simply wasn't enough light in the scene for the camera. In fact, to get color on the stationary car with no headlights, I needed to use a 30ms shutter with a gain of 70. Headlights/taillights actually improved the ambient light so I was able to drop to 20ms with a 70 gain. With those parameters, HLC was somewhere between doing nothing and making things worse so I disabled it. I also couldn't see any real difference when I changed noise reduction so I just left it at 50.

The current pictures aren't great but are adequate for our design objective (identify make/model and color of car). The images of people at night are basically useless, but I don't think we're going to change that without adding lighting and it's low priority for us anyway. I'm declaring victory...

Thanks to all for your suggestions.

 

[Mike A.]

Better for what you're going for. Have you tried just running it on auto? Wouldn't suggest that in most cases but for your purposes that or shutter priority might get you there better.

 

[steve0805]

Better for what you're going for. Have you tried just running it on auto?

Yeah stationary cars looked great in auto mode, but moving cars were really blurry. I figure the cars are going 15-20mph at the capture point, so with my 20ms shutter they travel ~6" during each frame--already not great. With auto mode's slower shutter, they probably move 1-2 feet.