Missed recording

[corylackey]

My system will pick up and record a leaf twitching in the wind but I can have someone in a car pull up and walk to my gate right in front of the camera and it does nothing. Wifi is good. Why does it do that?

[DannyBearAgain]

This issue seems to come and go from time to time, many users here have posted similar experiences.

Only arlo knows what their problem is but they keep it quiet.

[jguerdat]

Conspiracy theories get us no place. 

It's likely the sun's IR reflecting into the camera's sensor. It's not specifically the leaf moving but moving to a place where the sun's IR is directed towards the camera. Same thing with the car. The sun's angle changes over time so this doesn't always happen (more or less according to seasons) so making changes to the camera's view and/or motion sensitivity can help. 

[StephenB]

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@jguerdat wrote:

It's not specifically the leaf moving but moving to a place where the sun's IR is directed towards the camera. 

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The IR from the sun is a factor, but not the only one.  The PIR sensors used to detect motion are also used indoors to turn on lights in dark rooms when someone enters.  So other heat sources will trigger the sensors.

In this specific situation, it can also be due to wind thermals (the wind blowing leaves is a different temperature from the still air).

The camera positioning also matters.  The PIR sensors are most sensitive to side-to-side motion, and are more sensitive at the bottom of the field of view than the top.  If the car is driving directly toward the camera down the center of the field of view (or a person is walking that path), then the camera might not trigger.

And of course distance...

• https://kb.arlo.com/000062617/How-far-away-can-Arlo-Cameras-and-Arlo-Video-Doorbells-detect-motion

Though my own cameras will often detect things further away that this table indicates - generally vehicles (particularly emergency vehicles).  But they do not detect them reliably.