LPR Night Time Settings

[Mighty Chris Gill]

Hi Can any one help with some guidance on exposure setting and such to capture plate numbers at night? We have our cameras so they take superb shots when our test vehicle is static but when it is moving it is just a blur.
Its a fairly High end Vivotek Camera and is using a fairly grunty IR Led array.

Thanks in advance

 

[bigredfish]

Distance, speed, ambient light, angle of attack, and other factors can play a role, but the biggest factor is usually Exposure/shutter speed. Generally most are running 1/1000 - 1/2000 exposure, as little DNR as you can stand, and up the contrast. Use of WDR isnt recommended at night, but HLC can be helpful in some situations.

My Night settings for one at 120ft, bad angle 30+ degrees. I run same but 1/1000 during the day.



Generally you will only see the plate and small dots for headlights/taillights



(chnage youtube player to 1080p, Pause at 0:04 for tag capture)

 

[tigerwillow1]

I'm running a dahua HFW4231E-SE 6mm, close to the traffic, with external IR. This is what works for me:

Picture: Style standard, brightness, contrast+saturation+gamma all at 50, sharpness 0.
Exposure: anti flicker outdoor, mode manual, shutter 1/500, gain 10~60, 3d dnr off, grade 46.
Backlight: HLC @ 100, white balance auto.

I'm using the camera's automatic day/night profile switch. Without that the day picture would be useless.

 

[Mighty Chris Gill]

Thanks for the advice . MCG

 

[Laserray]

I'm heavy on the HLC -> 70
Tune focus in the day, and then set to manual.
Everything else is the same as above or fairly close.
Thats for night mode.
I think we all switch between day/night mode. Some use the Surise/Sunset program. Others use schedule. I use web commamds via Python code.

Good Luck

 

[EssDeeEll]

View attachment 48695

Hey BigRedFish, can you explain why your gain starts at 10 and what this does? I always wondered why there was an option.

Also you have a manually adjustable iris? Do you balance this with the shutter? Mine is either auto or off so I leave it off.

Thanks in advance.

 

[bigredfish]

As to the iris, I found by playing with it that anything over 40-45 created more IR washout. Can’t say as I fully understand it, but learned from member @nayr that especially at longer distances, it allows me to go to say 1/2000 and by dialing in the iris I get the right amount of light. Auto Iris decides by itself and doesn’t always give you the best image at night at 120ft

On the gain, just trial and error. Maybe a smidge more brightness at 10-0