To Adjust the smart event pre-record and post-record you need to follow these steps:
1) Log in to the NVR/Camera
2) Go to Configuration > Storage > Schedule Setting > Record Schedule
3) Click the 'Advanced' button at the top right of the record schedule
4) Select the duration you want from the pre/post record dropdowns and click OK
One thing to be aware of with event pre/post-recording is what Hikvision call a Buffer Zone. The buffer zone is simply a bracket of footage around the current moment in time that is continually recording/erasing, this buffer zone allows you to record only by event but still have access to footage before and after the trigger event without having continuous recording enabled.
The issue is that the buffer zone is limited to around 2-4MB of storage and so the higher your resolution and stream settings the larger the files sizes are and thus the maximum duration of the buffer you can use is limited. So basically an 8MP camera will not be able to have as long pre/post recording durations as a lower-spec 4MP or 2MP model. (unless you reduce the resolution/stream settings of the 8MP camera)
We recommend that to get the longest duration possible from your pre/post recording you should set them to the not limited option to use the full 2-4MB buffer capacity.
(One other thing to be aware of, there is no advantage or disadvantage for pre/post recording when using an NVR. Although the NVR is managing the event recording, each channel on the NVR is still set to the same 2-4MB buffer, the same as the individual cameras. So you would not get more pre/post recording capacity with 1x 8MP than you would with 8 x 8MP cameras on an NVR.)
Written by(One other thing to be aware of, there is no advantage or disadvantage for pre/post recording when using an NVR. Although the NVR is managing the event recording, each channel on the NVR is still set to the same 2-4MB buffer, the same as the individual cameras. So you would not get more pre/post recording capacity with 1x 8MP than you would with 8 x 8MP cameras on an NVR.)
I've had my Hikvision set up a few months now and I've noticed something has changed. I thought it was explained by what you said above but after some testing it isn't.
I started with 2 x 4 Mp cameras and Event recording only and I got the 5s pre-record period (or whatever I set it to) and never thought more about it.
I added 2 more 4 Mp cameras and moved to Continuous recording but noticed that when using the NVR playback in Event mode all the events started late or just a few seconds after the trigger point.
I read your post above and thought "aha, so that's why". It didn't bother me too much as iVMS worked and I had continuous recording so all the footage was there if I needed it. However, it was bugging me so I did some tests.
I took 2 cameras out of the system so that it was as it was when I first had the system.
When using the Event recording only I get the pre-record as I remember when I first had the system, but only in the Normal playback mode. In the Event playback mode all the events still start late even though the footage does exist and you can see it in Normal playback when only events are show on the timeline.
So I think there is a bug here that could make a user think it is the buffer issue (it seems to be strange that this should exist at all when there is whole HDD to record to - but it is what it is) but in fact it isn't in this case as the event playback is always late whether I record with 2 or 4 cameras, and with or without Continuous recording (which ensure the footage exists).
What seems to be wrong is event playback starts at the wrong time regardless. I don't recall this so I wonder if this is a recent firmware bug? Or maybe when I started out I never used playback in event mode as I only had events recorded anyway.
