What type of MotionSensor is this?

[gizz]

I clipped this from the Panasonic Web Page about the MotionSensor Feature on the PV-D series Palmcorders. Can anyone tell what type of sensor(Passive/Active) this is based upon the following?:

Special Features
Motion Security may mistakenly start
when:
• background is plain, like a white wall, or
has distinct vertical, horizontal, or
slanted stripes, like a venetian blind.
• brightness suddenly changes.

Motion Security may not start when:
• motion is very slow or fast.
• moving object is very small.
• motion occurs only in 1 corner of
viewing area.
• in poor lighting (in this case, MOTION
SECURITY flashes).
• background is plain, like a white wall, or
has distinct horizontal or vertical stripes.

Security Mode
Before you begin...
•Connect Camcorder to power source.
Use AC Adaptor for longer recordings.
•Insert cassette with record tab (page 11).
•Set POWER to CAMERA.
•Securely position and aim Camcorder.
<< I clipped all the setup stuff that was here >>
• Recording will start about 3 seconds
after motion is detected.
• Date and time are recorded if
displayed in EVF (page 16).
• Recording stops about 30 seconds
after motion ceases.
To cancel Security Mode, set POWER to
OFF.
Note:
• Security recording starts if Camcorder is
bumped or repositioned.
• This feature is not available during normal
recording.
• While in Motion Security stand-by, the
following functions are not available:
Record/Pause, Stand-by mode, Digital
E.I.S., Video Effects (Auto/Digital Fade).

[Archilochus]

Hi gizz,
This is my guess.....
Since the "motion sensor" can get fooled by vertical / horizontal stripes in the background, it's surely not a pyroelectric element (the type we all use in our PIR sensors), an "active" IR, or any type of ultrasonic or microwave field detector. ###So I'd have to say it's probably a video signal level-change detector. ### The computer in the cam monitors what the cam is "seeing" and when a certain amount of change occurs in the scene it turns on the recorder.
This technique is sometimes used in high end indoor security installations, but it has many limitations for "trail-cam" use - one of them being lots of power used 'cause the cam has to be on all the time. The other big problem is that outdoors scenery is always changing - wind blown trees, clouds passing over making the scene suddenly lighter / darker, etc.

Archilochus

[gizz]

Arch - Thanks for the clarification. I figured it was too good to be true for remote trailcam use. Guess I'll stick to what I have for now.