If you just want a recording, and the quality of the recording and/or it's usefulness aren't really a factor, then you can skip the rest of this post. But if the quality/usefullness does matter, then, it's all about defining the specifics of the job you need the system to do, under your specific conditions.
So...the point of the question I was asking isn't about a feature with facial recognition inside the device--even if a device had such a feature, it would require an internet connection to a database of faces with id's to do such a thing, so is only useful for specific faces that have already been documented in that specific database.
It is about resolution and clarity being able to use the video as evidence of a particular person or event, etc., if that's your goal.
If you only care to see that something happened and that a person was there (vs a bear or a racoon, etc
), it doesn't take much of a system to do that.
If you need to prove a specific person was there, it has to be clear enough and high enough resolution to prove it was them and not just someone with the general features, size, etc. What is clear to you might not be legally sufficient.
Clarity means ability of the system to focus, and the clarity of the recording (not blurry, and not like old TV pictures with all the various kinds of distortion, color problems, overbrightness, too dark, etc.).
It's a separate thing from resolution, which is just how many pixels the CCD is, and how many pixels are recorded (which can be different, and that's a separate problem). You can have a very high resolution that's useless because the picture is not clear for one reason or another.
Then you have the frame rate--the number of times per second that the CCD captures a scene, and the number of itmes per second that the recording device captures the data the CCD sends (which can be differnet, and that's a separate problem).
Also, if hte system uses compression in the video recording, that loses data and can cause all sorts of problems with usability of the recording, especially with movement--the faster the movement the more data is lost especially with high compression rates.
Then there is lighting capability--does the camera take low-light images well, as well as those in direct sunlight? If the camera blurs out when it gets bright or when light changes from dark to bright, etc., you lose data. If it blurs out during the transition from light to dark, especially if it has to change modes from regular light to IR, etc., some systems don't do this very well, and some have terrible IR lighting, requiring external IR setups that evenly light the area from all angles, rather than the built-in ring around the camera that only light the things directly facing the camera, and either only light things well that are really close up, or wash out things that are close and only light things well near the middle of the IR range, etc.
So...before you get a system, test it, or find someone that has it in similar conditions to yours so you can test it there, or make sure you can return it, etc.
