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IR watching another IR camera - Motion Detection >>

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I have a CNB LBM-24VF that is overlooking a baby's room that has a crib side baby monitor which uses IR. Everything is fine during the day but things get interesting with both cameras in IR mode.

 

The CNB's motion detection never turns off even though there is no motion. I also get a pixelated box effect around the baby monitor every 6 sec or so. The odd part is it only visible during live play and does not show up on the playback. The playback just shows a flicker every 6 sec not the pixelization. If I turn the baby monitor off the CNB in IR mode works fine so it has to be something with the way it is seeing the other IR camera.

 

Has anyone ever seen this? Are there any settings on the CNB camera that I can play with to try and resolve?

Thanks,

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Well that is a weird problem...

 

I am thinking maybe the IR LEDs are flickering on the baby monitor. Does it transmit the audio with IR? That would make it more likely to show a 'flicker' effect when a camera looks at it. Live-view probably compresses video a lot more so the flickering makes it get all blurred.

 

Not sure how you could go about fixing this...

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I have a young kid... and I choose not to have IR cams staring at them all night. I don't think enough studies have been done analyzing the long term effects of IR exposure.

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No reason it should be any "worse" than red light - it's just marginally longer wavelength.

 

In any case... some designs control LED brightness by varying the duty cycle of the power source - in other words, by flicking the power to them on and off quickly. It's possible, if the monitor's LEDs are being dimmed this way, that they're slightly out of sync with the CNB's shutter. If the CNB has the ability to adjust the shutter speed, try tweaking that.

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No reason it should be any "worse" than red light - it's just marginally longer wavelength.

 

Soundy is a doctor and a scientist now to?!

 

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I have a young kid... and I choose not to have IR cams staring at them all night. I don't think enough studies have been done analyzing the long term effects of IR exposure.

 

Nothing to worry about as IR is all around us at all time. Wait till your kid want his or her first cell phone. Don't get me started on Happy Meals... Don't worry!

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I have a young kid... and I choose not to have IR cams staring at them all night. I don't think enough studies have been done analyzing the long term effects of IR exposure.

 

Nothing to worry about as IR is all around us at all time.

 

I understand. However, it's not artificial and we at least get breaks from it at night.

 

Everything in moderation!

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Thanks for the replys. Yes, it does do audio as well. Why does that make it flicker more?

 

The camera is a LBM-24VF so it does have shutter speed settings of 1/60, 1/250, 1/700, 1/1K, 1/1.6K, 1/2.5K, 1/5K, 1/7K, 1/10K, 1/30K, 1/60K, 1/120K. What would be the perfered speed or will it just be trial and error until I find a setting that works?

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Manually adjusting the shutter may eliminate the problem. Not sure how well because whatever is controlling the IR LEDs probably isn't perfect in terms of timing...

 

IR is all around us. From lights to the sun, even your TV remote. I don't think that emission is dangerous in any way.

 

However, a strong IR illuminator is a different story - I have a cheap chinese one that I can feel a bit of heat from if I put the back of my hand in front of it. Strong IR can't be good for the eyes!

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I think it's working like Soundy says and pulsing the LED's. Continuously variable analog control would waste power. With one camera slightly off time with the other, there's a beat note in the lighting. Another source of IR fill in light would probably kill the problem.

 

They might sync up if they were both put on a 24VAC source.

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That all makes sense. I will play around a bit this weekend and let you know if I find a soultion. The baby monitor just plugs into the wall so it son 110 not 24 so that could be part of the problem.

 

Wonder if if I could disable the IR on the CNB and the IR from the baby monitor would surfice for both.

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Wall power is irrelevant - pretty much guarantee there's an internal power supply that knocks it down to ~12VDC. IF the LEDs' brightness is being controlled via duty cycle, it's probably using some internal clock source, not the 60Hz line voltage, and while it may "drift" a little, I think it's more likely that it's just slightly off the camera's shutter speed - for example, the camera may be using a 1/60 shutter speed, while the LEDs are running at 58Hz, which means they would be close to in-sync most of the time, with the odd "burst" that you're seeing.

 

Turning off the camera's IR wouldn't help, as the problem (assuming my theory is correct) is not interaction between the two, but just timing differences between the camera's shutter and the monitor's LEDs. If anything, you'd want to disable the monitor's LEDs.

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I have a CNB LBM-24VF that is overlooking a baby's room that has a crib side baby monitor which uses IR. Everything is fine during the day but things get interesting with both cameras in IR mode.

 

Why do u use IR on baby monitor ?

your CNB already has IR ?

Thx

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Why do u use IR on baby monitor ?

your CNB already has IR ?

Thx

 

I missed that point first read through. I was thinking he had two CNB's interacting and that would be fixed by using 24VAC. With a baby monitor, I don't think it's going to make any difference to change power source on the LMB24VF. Disable the LED's on one or the other camera if that's possible. Maybe duct tape?

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The baby monitor is actually in the crip and has advantages over the CNB such as the portable viewing device and nice music selection (for a 2 month old) . The CNB overlooks the room which is why I have both. Hopefully this weekend I can try disabling the IR on one or the other and messing with the shutter speed. Both of those are great ideas.

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IF the problem is that the camera's shutter and the monitor's IR are out of sync, then disabling the camera's IR won't change a thing.

 

Rather than starting with hardware hacking, I'd suggest changing the shutter first... takes about 20 seconds through the on-screen menus and is easy to undo if it doesn't help or makes things worse. I'd start with going to the next-slower shutter speed and see if that eliminates or at least changes the nature of the problem - that's a quick way to test if my theory is correct.

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I cant get the shutter to adjust. Under lens it is setup as DC and FLK is off so it should let me adjust. It only has 1/60 selected and I cant change it.

 

What is "FLK". Manual says flickerless but what does that mean.

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I cant get the shutter to adjust. Under lens it is setup as DC and FLK is off so it should let me adjust. It only has 1/60 selected and I cant change it.

 

What is "FLK". Manual says flickerless but what does that mean.

 

How far CNB from monitor or crib ?

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11 feet.

 

I changed the motion sensitivity to very low and taped over the monitor IR. It still bleeds pretty bad through the case of the unit so the CNB still see's it but it is not triggering the motion like it was. The picture pretty much sucks from the monitor now but it is usable.

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I cant get the shutter to adjust. Under lens it is setup as DC and FLK is off so it should let me adjust. It only has 1/60 selected and I cant change it.

 

What is "FLK". Manual says flickerless but what does that mean.

Does that camera have an ESC setting? Try toggling that...

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ESC = Electronic Shutter Control: camera controls exposure by varying the "shutter"; in effect, limiting the sample time of the chip. If this is enabled, it may be blocking your ability to set the shutter manually (dunno how CNB handles this, I haven't played with the setting).

 

DC = Direct Current, meaning DC-drive auto iris: the camera controls the iris opening of the lens by varying the voltage sent to it. This should have no effect on your ability to set the shutter speed.

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