Please see the attached image. These are both Dahua 1/2.8mm cams from one corner of the house. I have another one on the other side of the house and plan to install one more on that same other side to overlook the cars. I have one more cam covering the front entrance (kind of useless due to the angle) and could possible add another really wide angle cam just to get some overview (though I don't really look at the cams much, it is more that can catch the details if something is happening). So having given that information, do you think the overlap of maybe 4 feet at the walkway is sufficient? The cam on the left is fixed focal (dual lens) so I don't have much flexibility. I sure with all cams would be vari-vocal so you can just adjust it by some 2mm (in my case probably 0.5mm).
Overlap
- Thread starter rfj
- Start date
That should be sufficient. Basically is there any spot out there that someone could stand and not be seen?
Also get rid of one of the times on the cameras - in the event it is needed for the police, two times off that much will be problematic.
Also get rid of one of the times on the cameras - in the event it is needed for the police, two times off that much will be problematic.
Any angle for people coming from the street is covered from the left and from the right. Though barely, i.e. maybe 4 feet overlap. But there is a slightly bigger overlap from cams from the left and from the right.
The times are a bit annoying. I try to have the time embedded by the camera so that BI doesn't have to re-encode the video with the correct time based on the computer. However, the cams don't seem to keep up well with time from the computer. I did actually google this in the past and it seems BI can keep track of time if you use their video format. I need to look into this again...
The times are a bit annoying. I try to have the time embedded by the camera so that BI doesn't have to re-encode the video with the correct time based on the computer. However, the cams don't seem to keep up well with time from the computer. I did actually google this in the past and it seems BI can keep track of time if you use their video format. I need to look into this again...
Flintstone61
Known around here
aadje93
Getting the hang of it
Windows 10 pro at least has an I ternal ntp server that doesn't need external software. I always install the pro version so don't know if it's available in the other 2 versions. But it's just a few registry edits to enable it, and a firewall rule to allow the ntp protocol through, out of the head it was port 123,but could be wrong. Then your cams are at most 1 second off, and just let them ping ntp like every hour or so, it's local lan, and you don't have 500 devices asking what time it is every hour
I am not quite following. My Windows PC always has the right time. The issue is that the cameras sometimes 'lose' the time or they don't adjust to daylight savings time, etc. Is there some solution to keep the camera in sync with the computer, e.g. something is updating the time on the cams every 24h? Of should I just disable the time from the camera and have BI embed it?
As for the original question, I guess I am fine with this overlap. I don't have full coverage of the entire area but I do have full coverage (some 4 feet overlap) for where someone would enter into our property (from the street)
As for the original question, I guess I am fine with this overlap. I don't have full coverage of the entire area but I do have full coverage (some 4 feet overlap) for where someone would enter into our property (from the street)
aadje93
Getting the hang of it
Do your cams have internet connection? (security hazard) if they do, use pool.ntp.org as your time server in the camera network or time settings. It's called NTP or something like network time. Also the interval is not always changeable by the user. Sometimes it's locked.
NTP is a very old protocol still in use to synchronize time on computers and all kinds of devices, the computer or camera asks the NTP server what time it is, and then it get response of time within 100 milliseconds. So for general applications being 1 second off doesn't matter.
Now your local blue iris pc can also work as a ntp time server if your cameras are in a seperate vlan, I suppose not seeing you asking the question. As the cams wouldn't have internet (better security)
NTP is a very old protocol still in use to synchronize time on computers and all kinds of devices, the computer or camera asks the NTP server what time it is, and then it get response of time within 100 milliseconds. So for general applications being 1 second off doesn't matter.
Now your local blue iris pc can also work as a ntp time server if your cameras are in a seperate vlan, I suppose not seeing you asking the question. As the cams wouldn't have internet (better security)
Gargoile
Getting comfortable
This is what I have running on my BI with no issues. It's also easy to set up too.
My cams have not internet connection except through VPN. I had security issues and then blocked them from opening any port in my router. Currently, the cams are on the same LAN as all other devices (computers, phones, AppleTVs, AVRs, etc). They are on a separate 16 port PoE switch, though and I can create a separate VLAN for them. But the main point seems to be that you don't want BI to embed the time. Instead. you want the camera to embed the time into the video stream (recorded with direct to disc) and have some tool like BI update the time on the cams.
aadje93
Getting the hang of it
So, I will explain.
On your BI machine you need to setup a NTP server/relay. And then in your cameras setup the bi machine ip address as the ntp server. Then your cameras will all synchronize their time with what windows on the BI pc tells them. It's not BI doing it, it's the ntp server on windows.
On your BI machine you need to setup a NTP server/relay. And then in your cameras setup the bi machine ip address as the ntp server. Then your cameras will all synchronize their time with what windows on the BI pc tells them. It's not BI doing it, it's the ntp server on windows.
And keep in mind many here in legal and law have said that in court, BI overlays could get the video dismissed as that is considered altering the video.
It is best to setup a NTP on your computer, point the cameras to it, and set up DST in each camera.
It is best to setup a NTP on your computer, point the cameras to it, and set up DST in each camera.
Huh, that is crazy. As if I would video edit some dude walking into our yard and steal things and nobody can see that it was edited. But thank you for pointing this out. I guess I need to disable the BI timestamp and try to have the cams keeps up with time. Then again, here in California land if you steal something less than $950 it is considered a misdemeanor and because our prisons are overfilled you walk right out of prison again if they even put you in prison in the first place. I know of stores that have policies that you can't touch a "customer" that walks out with your merchandise that wasn't paid for. One wonders why to even bother putting up cams...
aadje93
Getting the hang of it
Flintstone61
Known around here
Don't even get me started.
I'm opposite, BI is my timestamp, and the camera's are not displaying their own clock. Why? because some of them have such a goofy Daylight saving time adjustment, and my DVR also needs to sync w PC, and the BI computer is my central repository for"time". I'm still running the Net time serveranyway.
Using the BI timestamp, hasn't stopped any cops from taking my video.
What would be more controversial is having two time stamps showing, and a defense attorney might have something to grab onto for dismissal I suppose.
when I send Law enforcement my LPR shots, i want/need to have a matching overview camera timestamped within the same second and with the same font and same placement.
It clears up the question I get when they ask if its the same car.
I'm opposite, BI is my timestamp, and the camera's are not displaying their own clock. Why? because some of them have such a goofy Daylight saving time adjustment, and my DVR also needs to sync w PC, and the BI computer is my central repository for"time". I'm still running the Net time serveranyway.
Using the BI timestamp, hasn't stopped any cops from taking my video.
What would be more controversial is having two time stamps showing, and a defense attorney might have something to grab onto for dismissal I suppose.
when I send Law enforcement my LPR shots, i want/need to have a matching overview camera timestamped within the same second and with the same font and same placement.
It clears up the question I get when they ask if its the same car.
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Flintstone61
Known around here
It's Friday, why am I up so damn early.
bigredfish
Known around here
Why not crossing cameras?
(* Excuse the filthy lens, we're in the process of moving and I havent cleaned them in a month and they have crud caked on them for the 5/21 storm)
(* Excuse the filthy lens, we're in the process of moving and I havent cleaned them in a month and they have crud caked on them for the 5/21 storm)
@Flinstone61 that is exactly my feeling. I don't like the fact that I have to run another program to sync the time stamps on the cams. It seems some people had issues with video being thrown out because it was embedded with BI. I find this kind of ridiculous but I can imagine it has happened. Maybe I shouldn't worry too much about it and most judges are reasonable enough to accept a time stamp being embedded into a video stream by a something else than the camera (like BI).
@bigredfish I do actually have cams from both sides. See attachment in the first post for the cams on the left. I have another cam that covers the sidewalk on the very left (CamLeft.png). Then I have one cam from the right (CamRight.png) which covers most of the area the left cams cover, just from a different angle. I am in the process of limiting that field of view and add another cam at a similar position and concentrate more on the right side (left looking from the street) to cover the rest or the driveway.
Why am I still up? Oh, it was graduation night and I had to work...
@bigredfish I do actually have cams from both sides. See attachment in the first post for the cams on the left. I have another cam that covers the sidewalk on the very left (CamLeft.png). Then I have one cam from the right (CamRight.png) which covers most of the area the left cams cover, just from a different angle. I am in the process of limiting that field of view and add another cam at a similar position and concentrate more on the right side (left looking from the street) to cover the rest or the driveway.
Why am I still up? Oh, it was graduation night and I had to work...
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I don't know if @wittaj has explained it this way, so I will. You don't have a problem until you do. For minor crime, of course this isn't going to come up. No petty criminal is going to hire an attorney that will pay this much attention to a "minor detail". Those petty criminals hardly ever even make it to court, so even if their attorney is aware, it probably won't come up.
But, you have to consider the "what if". What if 2 of your cameras pick up a murder and the video gets thrown out because the video was "edited"? How're you going to sleep at night with that? I know the chances are low, but think of it as cheap insurance.
sebastiantombs
Known around here
I started using NetTime for time sync across my cameras years ago when reducing CPU loading in BI. It does add to CPU utilization to add the time stamp in BI and back then, before sub streams, it was another way to get things under control. It isn't hard at all. Yeah, a few cameras need to be tweaked for time zones to handle DST, but I think DST is going away next year, nation wide, and even if it doesn't that minor tweak for time zones isn't a big deal. All my cameras are synced as exactly as the video streams permit and are unmodified from camera to disk. That's important in court with the way land sharks get cases dismissed whether we like it or not.