Motion detection first experiences, limitations and workarounds:

I recently bought a EufyCam E system with a couple of door sensor and wanted to share some thoughts about the motion detection system.

I had some frustration at first, finding myself needing to raise the sensitivity to reach far enough in some areas, which in turn made the system too sensitive and unstable.

After analyzing the way the motion detection work, I think I understand the limitations (inherent to most systems) and found ways around it.

I went from having to use 95 sensitivity to reach where I wanted, which was unstable, to being able to use 60 and reach farther with a stable system. Read below if interested.

Note: The camera in its default orientation has a 140 degree of Visual Horizontal Field of View. The camera Image appears to be 16:9, so that means the Visual Vertical field of view is about 79 degrees.

Eufy manual shows a drawing that is more like 75 degree of Visual Vertical Field of View, so not 100% sure what the exact number is.

I have two zones where It was more important to reach far away and up close than wide (far to the left and right).

I noticed that with the camera in its default Landscape orientation, placed at 7.5 feet high with about 30 degree down-tilt (so I could capture close under the camera), it would not detect beyond 19 feet unless I cranked the sensitivity up to 90+ which in turn would make the system unstable (lots of false alarm).

I realized this was likely because, as shown on the camera manual, the motion detection vertical Field of View is less than the Visual Vertical FoV, creating a dead zone at the top of the camera view (good not to catch birds).

Doing some basic calculation, it looks like the top 30% of the camera view is almost dead for motion detection. And probably the bottom 15/20% too. Motion detection takes place in the vertical 55% between these two dead zones. Of course this may not be a hard limit but a fuzzy one based on sensitivity level.

But at a reasonable sensitivity level, you can expect object moving in the top 30% and bottom 15% not to be detected. Now even in the hot middle detection zone, there will be a distance limit of about 30 feet.

This is likely why Eufy advises not to tilt the camera more than 30 degree, as this will start limiting how far you can detect.

If the camera is fairly horizontal (un-tilted), you will be able to reach the full distance (30+ feet), but as you tilt more, it will reduce the max detection distance.

The manual does not show what is the horizontal reach or the motion sensor, so assuming it was about the same 140 degree as the optical camera, I decided to try and work around the limitation, by tilting the camera 45 to 90 degrees. This allowed the far away areas to be covered in the bottom two third of the image and therefore to be in the active motion detection zone.

I am happy to report that the results were actually pretty good. On the side of the house, instead of having to use a sensitivity of 90+ for just 19 feet reach (and plenty of false alarms), I could go down to a sensitivity of 60 with 30 feet reach.

Suggestion to @AnkerTechnical:

Given the above (and if my assumptions are right), it would be nice is if we had the option to rotate the viewer and change its ratio so we could better visualize the videos resulting from a tilted camera. If the camera is tilted + or – 90 degree we need the viewer to have a 9:16 aspect ratio (instead of 16:9) and the ability to rotate + or – 90 degree

Because of the dead zone I can even imagine situation where flipping the camera 180deg would help, so we would also need that rotation option for the viewers (basically 90/180/270, with aspect ratio change for 90- and 270).

2 Likes

The ability to rotate was requested almost a year ago so wouldn’t hold you breath

Good find though, will try that with mine, hopefully make it not as useless until I replace it with something that works properly

My camera hangs about 10 feet above the ground.
If the only solution is to tilt the camera between 45 to 90 degrees I will only record what is just below the camera at the front door. But I would like to record also the drive way.

I don’t think you understood what I meant (or Id did not what you meant :slight_smile: )
If your camera is high up, and you want to capture what is close to the camera you would have to tilt it down quite a bit.
If so, then the motion detection would not carry very far. In that case and if you don’t need to reach far on the left and right side, you could rotate the camera in the horizontal plane (not vertical tilt), so that your video image will be a portrait image Higher than wide, that will reach both close and far with motion detection, but les wide.

Thanks for this clarification. This tip is helpful.
With this position the camera is detecting motion from a bigger distance. I need also left and right but it is less important.

On some of my cameras, I actually used 45 degree, to get the best of both