Limiting EXIR coverage

lunokhod · Mar 30, 2018

Hi Everybody,

Just wondering if anyone has done any experimenting with limiting/blocking the IR illumination coverage with a Hikvision turret camera.

I've just installed another 4mm DS-2CD2342WD-I at home that is looking up a narrow path between my house and the fence. I've been in contact with my neighbor and told her I've installed this camera. I offered to cover her driveway with a privacy mask, but she is happy for me to monitor her driveway as she has had her garage broken into a few times.

Anyway, the big problem I have found is the light cream wall to the left of the image. At night, the IR illumination makes this so bright that the auto exposure makes the wanted part of the image way too dark.

I did think about rotating the camera more to the right, but then I am looking into my neighbors property a whole lot more... and I'm not comfortable with that. I can't physically move the camera to the right any more.

I was thinking about using a small aluminum "shutter" to block the IR light shining on the wall.

What are peoples thoughts about this?

Regards,

Michael.

Trax95008 · Mar 30, 2018

some firmwares will allow you to rotate the image 90*. If your able to do that, then you can rotate the camera 90*, so that the aspect matches the intended coverage area. I believe this will help in your situation

hiky · Mar 30, 2018

Have you tried rotating the lens so the IR is above or below the Iris instead of side to side, that should put the camera into corridor mode, then go into settings from a web browser UI and play with the settings to see if you get abetter image

Configuration > Image > Display Settings > Video adjustment ( at bottom ) there you will find ( Mirror ) and ( rotate ) a mix of different configs might help but you do have a narrow alley way there so it might be tricky, another thing to try is backlight settings, have a play with left or right to see if that helps with IR glare, the only other option is to add some daylight down the alley, maybe an energy saving 10w ext lamp and run the camera in daylight mode at night, the trouble is with the 2342 is they are not that good at night time work, great during the day but poor at night

alastairstevenson · Mar 30, 2018

lunokhod said:
I can't physically move the camera to the right any more.

The camera seems to be quite a long way out from the wall.
Is it possible to move it closer to the wall such that the area of wall visible to it is reduced?
When you have no choice but to look along a wall it's adverse effect on exposure is reduced when the camera is as close as possible.

lunokhod · Mar 30, 2018

Thanks for the input.

The camera is around 11.5" away from the wall.

I will look into using the corridor mode and rotate the camera 90 degrees. That might be the best option.

I experimented with blocking the IR light last night, unsuccessfully. Due to the way the EXIR IR lens works, you can't easily block off the coverage. The moment you try to shield the IR light with a vertical shield, you get IR light reflecting back into the camera lens and it washes out the image even worse.

I have also thought about disabling the EXIR illumination and using an external IR illumination source that can be aimed away from the wall surface.

More experimenting to come.

Michael.

Tolting Colt Acres · Mar 31, 2018

lunokhod said:
I have also thought about disabling the EXIR illumination and using an external IR illumination source that can be aimed away from the wall surface.

If corridor mode doesn't work, this sounds like your best option.

pozzello · Mar 31, 2018

+1 for corridor mode (turn the cam sideways and rotate image 90' in the cam's UI).

Also, you seem top be running in 1080p mode (16x9 aspect ratio).
if corridor mode is too narrow, using 3MP mode will change aspect to 4x3...

triumph202 · Apr 1, 2018

@lunokhod I've got a couple of 2342's that I'm using in a similar situation. They both suffer from really bad IR reflections and I've ended up turning off the on board IR. I've instead set up PIR sensor lights (visible light) and have the cameras set to colour 24/7. You can run either mains powered lights or there are decent solar PIR lights you can use eg. Arilux's AL-SL12 . I've bought a lot of the AL-SL12 and use them around the house for security lighting.

One other mod that you should consider is changing the lens in that camera from 4mm. I've experimented with up to 16mm and had really good results in the 2342 Hiks. IIRC the camera I've got in a similar situation has got a 8mm lens fitted. (You do run into issues with focus on close subjects with the higher magnification lenses, so you need to focus them to suit the conditions.)

lunokhod · Apr 3, 2018

OK Everybody,

I've done my experimentation and have come up with a decent compromise.

I did try an external IR illuminator and this would have worked OK... but I didn't end up going down this path.

I ended up playing around with the Exposure and Back Light Compensation. I set up a Custom BLC zone centered on the path in the middle of the image. This improved the night time image a LOT. The wall to the left ends up being very overexposed, but this is not a concern for me.

Changing the Exposure Time to "Auto * 2(80000us)", increased the image quality significantly without too much impact on motion blur when a person walks down the path in the dark.

I didn't get a screen capture of a night time image last night to show you... I'll endeavor to do this tonight.

Corridor mode is still another option I am considering, but my neighbor is still keen on me monitoring her driveway.

Michael.

pozzello · Apr 3, 2018

you'll still get all of your and her drives in corridor mode, especially if you go to 4x3 (3MP)...

fenderman · Apr 3, 2018

pozzello said:
you'll still get all of your and her drives in corridor mode, especially if you go to 4x3 (3MP)...

I dont think those 4mp cams have a 4:3 option....could be wrong...

pozzello · Apr 3, 2018

doh. DS-2CD2342WD. nevermind. still, even 16x9 turned sideways will cover his drive and hers with a lot less wall.

lunokhod · Apr 4, 2018

Night shot with exposure and backlight settings changed.

alastairstevenson · Apr 4, 2018

You'd get a much better image if it was possible to get the camera closer to the wall, reducing the area of the wall that's visible to the camera.
Is that feasible?

lunokhod · Apr 4, 2018

alastairstevenson said:
You'd get a much better image if it was possible to get the camera closer to the wall, reducing the area of the wall that's visible to the camera.
Is that feasible?

It would be possible.

At the moment, the camera is mounted on a Hikvision mounting block attached to the eaves. There is a limit to how close I can get to the wall this way due to a 100x50mm plastic cable duct that runs the length of the wall/eaves. You can just make out a little of this in the top left of the image.

I could wall mount the camera below the duct (carefully as it is made from asbestos sheeting... gotta love the 60s).

pozzello · Apr 4, 2018

just turn the damned thing. really. you'll like it.

dunno how to embed images... oh well:
drive_s 2018-4-4 3.09.21.698 PM
drive_n 2018-4-4 3.09.03.184 PM

triumph202 · Apr 4, 2018

pozzello said:
just turn the damned thing. really. you'll like it.

dunno how to embed images... oh well:
drive_s 2018-4-4 3.09.21.698 PM
drive_n 2018-4-4 3.09.03.184 PM

Swapping to a lens with more magnification would also be worthwhile- there's not much point covering so much of the neighbour's yard.

Below is the same camera with a 16mm lens fitted. I've since changed it to a lower magnification as 16mm was a bit too much!

The gate is around 10-12m from the camera.

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Limiting EXIR coverage

lunokhod

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Trax95008

Getting the hang of it

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alastairstevenson

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triumph202

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