Common issues with camera image

bigredfish

Known around here
Joined
Sep 5, 2016
Messages
7,002
Reaction score
12,873
Location
Florida USA
Just a little experimenting shows that generally speaking the NI series does quite well during various daytime lighting changes in plain old AUTO exposure.
Blasphemy I know but it works pretty good ;)

Normal

Overcast with rain (count the rain drops!)

 
Last edited:

samplenhold

Known around here
Joined
Aug 8, 2018
Messages
2,509
Reaction score
5,351
Location
Spring, Texas
Have a question for the experts here on exposure. My LPR-E cam is facing NW and gets great plate shots. BUT at this time of year the sun is lower in the afternoon and is in the SW which, for a few hours washes out my plates if the car is travelling NW. See photo. Settings below. IPC-HFW5241E-Z12E


1609880152817.png

LPR East 2021-01-05 02.35.25.331 PM.jpg
 
Last edited:

tech101

Known around here
Joined
Mar 30, 2015
Messages
1,019
Reaction score
1,023
Location
SF BayArea, USA
I have similar issue.. However If I do go say 1/4000 what happens is if its a cloudy day or rainy day then the light is not enough at times..
 

tech101

Known around here
Joined
Mar 30, 2015
Messages
1,019
Reaction score
1,023
Location
SF BayArea, USA
That same problem is what made me play with Customized Range on Manual Exposure. Start around 0-2 and see how it works..
I am going to try this.. Thank you @bigredfish

1609886750939.png

Sorry for a dumb question .. What I have not understood is what is it means any chart like in ms..

0~2 is that like 1/1000 - 1/2000 ?

I have a dumb idea...More Camera's....:)
LOL, I been doing that haha
 

ajwitt

Getting the hang of it
Joined
Jan 1, 2021
Messages
86
Reaction score
92
Location
USA
The problem I had with a range for the shutter speed for my LPR was then it was taking photos every time the shutter changed because it would then cycle through an autofocus and of course then it would be a complete blur when a car came through at that time.

We just have to recognize that for LPR purposes that not every situation is going to be perfect, so we have to find the balance for our system. For some it is an issue at dusk/dawn times frames, others it is a washout with a morning or evening sun, and others it is a cloudy day.
 

samplenhold

Known around here
Joined
Aug 8, 2018
Messages
2,509
Reaction score
5,351
Location
Spring, Texas
I have a dumb idea...More Camera's
Luckily, I have a second cam (LPR-W) pointing in the other direction. The washout is only an issue for cars traveling NW on that street. Cars that travel in the opposite direction and those that turn onto that street from the side street do not have that problem. So if the car has a front plate, I get it on LPR-W.

Would any of the backlight options help?

@bigredfish I'll try the customized range tomorrow afternoon. It's too late for today.
 

bigredfish

Known around here
Joined
Sep 5, 2016
Messages
7,002
Reaction score
12,873
Location
Florida USA
The problem I had with a range for the shutter speed for my LPR was then it was taking photos every time the shutter changed because it would then cycle through an autofocus and of course then it would be a complete blur when a car came through at that time.

We just have to recognize that for LPR purposes that not every situation is going to be perfect, so we have to find the balance for our system. For some it is an issue at dusk/dawn times frames, others it is a washout with a morning or evening sun, and others it is a cloudy day.
At night I agree. It’s a mess and you have to use a fixed manual value.
But for daytime I find it works good.
 

bigredfish

Known around here
Joined
Sep 5, 2016
Messages
7,002
Reaction score
12,873
Location
Florida USA
Luckily, I have a second cam (LPR-W) pointing in the other direction. The washout is only an issue for cars traveling NW on that street. Cars that travel in the opposite direction and those that turn onto that street from the side street do not have that problem. So if the car has a front plate, I get it on LPR-W.

Would any of the backlight options help?

@bigredfish I'll try the customized range tomorrow afternoon. It's too late for today.
Yeah I use it on one of my 4 LPR cams. But because of a tree shadow, I have the opposite problem. On dark rainy days my fixed 1/2000 got too dark for a color image.
 

bigredfish

Known around here
Joined
Sep 5, 2016
Messages
7,002
Reaction score
12,873
Location
Florida USA
A trick I think I learned from @Wildcat_1 ?

set to manual, choose your fixed exposure - say 1/2000
Then while still on manual, click the rate drop down and scroll all the way down and select Customized Range
It will do the calculation and insert the right fraction for you!
 
Last edited:

Bryan

Getting comfortable
Joined
Nov 25, 2016
Messages
266
Reaction score
254
Question about newer Dahua cameras...seem they are placing the IR light behind the same glass as the lens on some cameras. One I recently bought had a washed out image with the IR on. Has anybody noticed this?
 
Joined
Dec 28, 2019
Messages
3,555
Reaction score
6,912
Location
New Jersey
I just installed two 3241T-ZAS cameras. The IR is behind the glass. I normally don't run IR on either of them because of ambient light and external IR illuminators. I did have to turn on IR in one of them and, yes, the video had a washed out look that can be eliminated or duplicated simply by turning the IR on or off.
 

Wildcat_1

Getting comfortable
Joined
Dec 9, 2018
Messages
878
Reaction score
1,499
Location
US
A trick I think I learned from @Wildcat_1 ?

set to manual, choose your fixed exposure - say 1/2000
Then while still on manual, click the rate drop down and scroll all the way down and select Customized Range
It will do the calculation and insert the right fraction for you!

Haha glad you remembered the trick I shared @bigredfish, nice to hear its useful :)
 
Top