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RustyJL

Sensitivity of Act 5611 motion detection

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Reading a few posts, appears video motion detection is flawed in that shadows can set the recording off.

 

How does the Acti 5611 fare in this department with the detection zones being set?

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Like just about all cameras with video motion detection, shadows change pixels, causes a motion detection event to trigger. You can attached a PIR motion detector to the camera, then it will be more accurate and won't be triggered by shadows or lights. I believe the camera has 12V out so it can even power the detector.

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Yes, it's not really flawed, in that it's detecting motion that is really there. These are not technically false alarms, they're just not the motion most people want to detect.

 

What you need is either the PIR based motion detection BW mentions, which detects motion using different signals (passive IR instead of pixels, which has its own advantages and drawbacks), or intelligent motion detection that allows you to fine tune the detection algorithms to detect what you consider important.

 

For instance, Blue Iris lets you detect motion due to color changes, contrast changes, or a combination of the two, as well as letting you set the sensitivity for the size and contrast of the changes. It also will let you turn on a mode that looks for groups of pixels changing in a similar pattern, to help differentiate between random motion (noise or shadows) and objects in motion. Each of these methods has plusses and minusses.

 

Most cameras don't have that complex a MD algorithm in place, but some may be better than others.

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Does the Acti NVR software have a similar capability to Blue Iris?

 

PIR would mean the subject of the event trigger would have to be fairly close to the camera?

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ACTi NVR uses the camera to detect motion or trigger on alarm inputs. A good outdoor PIR motion detector can go out about 40-60' but there are longer range PIR motion detectors. Problem with BlueIris is that it can not take alarm I-O or camera motion events. Yes, BlueIris is more intelligent at detecting motion but is CPU intensive. Be it as it may, when I had the shadow of my neighbors palm trees swaying in the wind, BlueIris still detected that as motion.

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Depending on which version of BI you tested, there were relatively recent changes to the MD algorithms to improve things like shadow rejection. I haven't updated to the newer versions on my main system, but initial reports are that they also reduce sensitivity overall when enabled, as might be expected.

 

Version 3.30.00 - August 6, 2013

 

Significant updates to the Motion Detector have been made in order to enhance its success rate. The key advancement in the algorithm involves filtering out potential objects which are largely due to changes in brightness only. You may visualize this change by enabling the Highlight motion option on the Motion/Trigger page in camera properties.

The downside to having a lot of variables in the motion detect settings is the amount of testing it takes to figure out what combination works best (if any). It's especially a trade-off if you want to catch night time action near the edge of your illumination yet still reject shadows, though the time-based profiles help with that as well (you can trigger them based on sunrise/sunset times for your latitude and longitude).

 

This doesn't help for people who want to run dedicated NVRs or edge recording, or do the processing on the cameras, of course.

 

 

For external inputs, BI will process alarm signals from Arduino, Sealevel, X10, and similar, though it's not very plug and play, depending on which system you choose. There are also users working with Raspberry Pi units and such. I haven't done any of this, so don't have any details on how well it works.

 

Arduino

 

The Arduino UNO is an open-source project board, available very inexpensively at electronics hobby shops or online via eBay. The UNO must actually itself be programmed to respond to data it receives via the serial port from Blue Iris. When an alert is triggered, Blue Iris will send a single byte of data to the UNO, an ASCII number 0-7 representing the output number specified on a camera's Alerts tab. Blue Iris also monitors for incoming serial data, and interprets each incoming byte as the 8-bits representing digital input numbers 0-7, which may be used to trigger the camrea.

 

Sealevel Systems

 

The Sealevel SeaDAC Lite (P/N 8112 and similar), although more expensive than the UNO, provides a more turn-key solution. You may simply connect your digital inputs and outputs; there's no project-board programming involved.

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