IVS nearly fabulous.....

[Dave Lonsdale]

IVS has eliminated all the false triggers from the internal IR caused by rain, snow, insects etc. Have external IR on order that maybe I don't need now.

But, why does it work perfectly overnight capturing the rabbits and foxes but not the car? See pictures.




I also had standard motion detection on this camera (as well as IVS) to get the car which, to be sufficiently sensitive, very often triggers constantly overnight.
The IVS target is the full field of view (8191 x 8139 but don't know what the units are) so perhaps it's because the car headlights spillover the scene? Don't think it's because the SW doesn't have time to find the car because it works OK in the daytime.

Associated query - does anyone know what the minimum time parameter is for a moving object prior to it entering an intrusion zone or tripwire? (I hesitate to ask does size matter.....)

Point of interest - notice how quickly the car headlights darken the background.

 

[nayr]

cars moving too fast and image is too dark.. use intrusion zone for vehicles, with 'appears' selected.. will work better.

the object has to stick around in view long enough to be detected as an object.. and the headlamps are screwing with your exposure.

 

[Dave Lonsdale]

Thanks nayr, I've changed the two intrusion zones to 'appears' but left all else as was. Will try out when its dark.

The speed of the car in the daytime when successfully detected is the same as when its dark. I was hoping that detection time would be quantitative rather than just qualitative.

Regarding the exposure, I was surprised to see it adjust in milliseconds - not something I've monitored previously, but perhaps that's normal for most cameras.

 

[nayr]

at night with those oncoming headlights your more likely going to detect 2 objects around the headlamps.. IVS in day is alot better at detecting objects

try removing both intrusion zones and make a single larger one covering most of the drive..

 

[Dave Lonsdale]

Have created one very big intrusion zone and deleted all the other intrusion zones and tripwires. Then driven through both fast and slow but still no joy. Works if I walk through. Will try again tomorrow, making sure I didn't make a mistake. For example, it appears that if motion is already in triggered state (which it is almost continuously this evening because of light rain - sensitivity 70 and threshold 5), it doesn't record the IVS triggers as well, even though in SPSS2, the zone flashes red when I walk through. This makes the IVS triggers harder to find.

Intrusion zone and tripwire boundaries don't even show in playback using my browser.

 

[Dave Lonsdale]

Can now confirm that, when using SPSS to view records captured on the camera's sd card, IVS records do not appear in SPSS when coincident with motion records. I didn't find a setting in PSS for this (I store records only on the camera's sd card to avoid the need to run the PC continuously). Coincident records are, nevertheless, listed separately using the camera's playback via the browser although IVS blue and flashing red boundaries are not shown.

Going back to the reason for this post, I have now reduced the motion sensitivity to 30 and threshold to 10 in an attempt to find a compromise whereby MD will only capture such things as vehicles at night without a flood of unwanted triggers and IVS will pick up all the more discrete events.

 

[Dave Lonsdale]

A perfect blend of motion detection and IVS intrusion was not found. With motion settings of 30% sensitivity and 20% threshold to guarantee catching what intrusion misses, this evening's rain still causes almost continuous alarm events. Nevertheless, I'm pretty sure that the external IR (when it eventually arrives) instead of the camera's built-in IR will nail the MD problem. Lucky they're not roving PTZs.

 

[Jack B Nimble]

I know with Hikvision you don't want overlapping lines also there is a setting for size of object not sure about Dahua.

 

[Dave Lonsdale]

Thanks for the tip, but through experimentation I have established that the Dahua 8231 intrusion zone boundaries are very tolerant to overlapping. Using advice from nayr, I have a test camera with one intrusion zone covering the entire area for detection set to 'Appears' that works well but then as belt and braces added another three narrow intrusion zones within but with overspill set to 'Cross'. All seem to trigger extremely well night and day except with car headlights at night.

I also noticed that with a second camera, having twitchy overnight PIR triggered lighting within its field of view, only MD triggers and not IVS both when switching on and switching off.