Subscriber Discussion

IR Camera Under An Eave Video Problems

U
Undisclosed #1
Nov 22, 2016

Noticed that when mounting an IR dome underneath an eave, if not enough vertical clearance is given between the dome and the eave, the IR LEDs reflect off of the bottom of the eave and bounce back into the lens, ruining the shot. The obvious solution is to mount the camera lower on the wall to increase the vertical clearance with the bottom of the eave. However, in sites where this is not possible, are there ways to mitigate this reflection?

(2)
U
Undisclosed #2
Nov 22, 2016
IPVMU Certified

Some domes have their IR asymetrically clustered, like this common Hik below. Maybe orienting the dome with the side with no LEDs would reduce the reflections. Also, increases light on target.

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Ethan Ace
Nov 22, 2016

What do you mean asymmetrically clustered? The LEDs are exactly symmetrical.

Also that picture shows the dome sideways. If you mount it in the normal orientation, the LEDs are toward the bottom of the dome. If you rotate the gimbal to properly orient the imager (instead of rotating in software) when mounted sideways, the LEDs would be in the same position (photocell down is typically "upright" for Hikvision, I believe).

In my experience, that does help, but I have at least one camera up that has this very problem, and it's mounted as low as I'd care to make it.

U
Undisclosed #2
Nov 22, 2016
IPVMU Certified

What do you mean asymmetrically clustered.

I mean they break Rotational Symmetry. Unlike this dome, which is rotationally symmetric, except for the photosensor.

I put the Hik dome on its side because the OP says its on the wall and because it makes more sense that there would be reflection from above.

If its on the wall, then rotating it so that there are no LEDS on the top might help, no?

U
Undisclosed #2
Nov 22, 2016
IPVMU Certified

If you can't use an asymmetrically clustered dome, perhaps you can block the IR with something dull and black before it reaches the eave, like an extension of the black plastic that typically is inside the dome.

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Sean Nelson
Nov 22, 2016
Nelly's Security

use jbox which moves the camera down more past the lip of the eave

(1)
JG
Jeff Gack
Nov 23, 2016
IPVMU Certified

You could turn the IR off on the camera and have the customer add some outdoor lighting to the scene or add a separate IR illuminator off to the side a bit where it won't light up the eave. Snow falling in front of the cameras IR can cause the same type of problem and be resolved the same way if it's practical and the customer is willing to pay for the extra lighting.

(1)
MB
Mark Bottomley
Nov 28, 2016

Could something as simple as some flat black paint on the eaves reduce the reflections enough? An experiment with black construction paper should verify the solution.

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Jon Dillabaugh
Nov 28, 2016
Pro Focus LLC

Does your cameras view need to see the bottom of the eave? Can't you simply aim the view lower? Is there something of importance that is above the height of the camera in the distance?

UI
Undisclosed Integrator #3
Nov 29, 2016

I have experienced this on my own home. The eave is not in the view, but it is white and does reflect a significant amount of ir back into the lens.

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Jon Dillabaugh
Nov 29, 2016
Pro Focus LLC

I, also, have white eaves and IR domes, but have never had any issues that I am aware of. I will have to go back through some footage to see if I can find any effect of eave reflection.

(1)
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