Dahua Global Calibration - Why should I care?

Sybertiger

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The funny thing is, with Dahua being such a large manufacturer of IP cams, you'd think they could do a better job of documenting, explaining, provided example videos or providing practical application tips. Instead of railing against Dahua and their shortfalls or digressing to tell that dog owner to get off my lawn let me just move on and try to get some help here.

The Global Calibration process, what can you tell me about the importance of this step? Is this simply a "newer" process to help cope with point-to-point perspective issues of the apparent visual size of objects getting smaller the farther they are away from the camera? The silly Min/Max size settings in the Dahua browser user interface certainly don't account for perspective. Maybe, I'm not supposed to be concerned about objects far from the camera and should be only dealing with Recognize/Identify distances when creating those stupid Min boxes. But, I would like to have IVS trigger an alert when someone is 20 feet away as would I if they were 100 feet away. I see that only some Dahua IVS cams have the Global Configuration menu. Is this an important step we are supposed to be doing when this feature is available AND we are using the internal IVS capabilities of the IP cams?

What can you tell me? Are we supposed to grab a yard stick then hold it in front of the cam at various distances then draw a line? Should it be done directly down the centerline sight of the cam? Or at an angle?
 

wittaj

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You have to remember that the homeowner isn't the Hikvision and Dahua target audience, it is the professional installers, so we cannot purchase directly and thus they will not take your phone call for support related questions - they will tell you to talk to the installer you purchased from. Many people have bought a Hikvision or Dahua from Amazon or some shady foreign website and when they call Hikvision or Dahua for support they basically tell them to go pound salt. We simply are not their intended market to sell to and they will not take your call for support...Lot's of threads here confirming this, including this one from a few weeks ago where someone tried to call for support and they told them sorry talk to your installer.

We are just fortunate to be able to get our hands on these types of cameras and a forum like this to help us troubleshoot when needed.

In "theory", these authorized professional installers are trained for these cameras and to know what every setting means, but the reality is I bet many of us here know more about these cameras than the professional installers.

As you alluded to, whether to do the global configuration comes down to your field of view, install height, etc. Most of my cameras I did not have to do the global configuration, but one or two of them I had to as they were false triggers.

Regarding an alert whether something is 20 feet away or 100 feet away, keep in mind that we often say try not to do too much with one field of view. Sometimes you may get lucking with a FOV that can do the big ranges in distances, but usually you would want 2 cameras for those distances.
 

Sybertiger

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quite a few threads already on IPCT... IVS Global Calibration - Detailed Questions

Search on Dahua's site revealed.... DahuaWiki
Yes, I had already read that thread. It wasn't conclusive so I thought I'd be a bit more specific regarding my question. It seems to be more of a "this is what I did" discussion. Haven't found anything yet that explains the exact purpose of this feature, what problems it solves or if it's necessary under only certain conditions.

I'd be willing to bet a lot of the pro installers simply go off of the basic default settings and maybe tweak it slightly only when it's obvious there's an issue. I betcha a lot of them come here looking for answers since this is the best website.

I shall keep looking and share anything useful I find.....if I find it.
 
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