IR washout on CCTV Cameras

[bmacdona 0]

I have an 8 camera GenIV system. I'm using DT-5690 IR Bullet cameras for the driveway & side yard cams.. They work VERY well during the day and twighlight. But at night they get washed out due to too much IR light (especially if the camera is pointed towards plant leaves or tall grasses). I have played with all of the controls on the DVR (GUI). But have not modified any of the settings that can be set in the camera (it has several settings that are set by buttons in the camera housing... AWB, BLC, AGC etc...).

Has anyone else had this problem.. and what did you do to correct it?

 

Example - at night I can easily recognize someone 35' away.. but if they are standing 5' away from the camera, they look like a glowing blob.

 

Thanks

[Soundy 1]

I'm guessing these cameras don't have auto-iris lenses? I can't find anything about them in a google search.

 

This, of course, is one of the drawbacks of cheap cameras with built-in IR...

 

AGC (auto gain control) *may* help...

[bmacdona 0]

I bought the cameras through dvrusa.com. They are listed as dt-5600F on their website. They have:

AGC, Auto-Iris, AWB, BLC as well as auto filter change. They work great in most applications day and night... but when they are pointing towards anything with lots of leaves or foliage... the IR light reflects back and blinds the camera. The camera that I have pointed into the back yard allows me to see very clearly in total darkness (at least 100'). But the cameras in the side yards are closer to trees and they get the IR reflection.

[Soundy 1]

Okay, so your problem is, you have cameras with very power IR capability, and it's naturally "overpowering" on close objects. Imagine if you took a spot light, something bright like the alley light on a police car, and shone it on a piece of paper three feet away - the reflection would be blinding. That's what's going on here - you have a super-powerful light source, and nearby objects that are highly reflective to that light.

 

So your options are either to adjust the cameras to avoid the foliage... move or remove the offending foliage... or disable the IR in the cameras (or swap to non-IR cameras) and use external illuminators that can either be placed so as to avoid lighting up the foliage, or that can control their output power as needed.

[SEANHAWG 1]

Like Soundy said, if you can lower the AGC, this will help dramatically. The only drawback by doing this is that you will have a darker picture at night especially on farther away objects.

 

We are currently testing a camera that initially had this problem due to its really high powered IR, beautiful low light settings, but just as you said, when someone walked right in front of it, it was just a white silhouette. But I was able to tweak the AGC and it helped 100%. Some cameras you can micro tweak the AGC more than others. On some cameras, it just has an On/Off setting. Hopefully your camera is one of those that you can raise or lower instead of just turning on or off.

[Soundy 1]

I dunno why the auto-iris wouldn't respond better to the IR... yet another reason I prefer motion-activated lighting over IR. A good low-light camera like a CNB Mona Lisa will give you better picture with very little ambient light anyway.

[BestGear 0]

Hi

 

I have had issues with several "cheap" IT cameras - just as you have.

 

What I have done, which you may feel is extreme(!) is openthe camera up and modify the IR LED positions.

 

What I mean by that is, adjust the LEDs so they are not all pointing straight ahead like a big "beam" and are more disperse.

 

This obviously looses you distance viewing, but buys you width and a far more ven illumination of the subject.

 

I do wonder why they are not made that way - or at least have that as an option when ordering as it makes far more sense to have the light "fill the frame" and not just a spot in the middle.

 

David

[yakky 0]

Not sure how to resolve it with the existing cameras, they are probably some settings you can adjust that might yield a better result but the real answer is getting cameras with intelligent DSPs. CNBs are particularly effective, I get no wash out on faces with my WBL-20S.