OK this is a simple matter but a lot of customers get these two settings confused, backwards, or think they mean the same thing.
Resolution is the size of the picture. A DVR can normally record at one of 3 setting options. CIF, Field and Full or CIF, 2CIF, and 4CIF which correspond to the same sizes. CIF is 320X240, Field or 2CIF is 704X240, and Full or 4CIF is 704X480 and also sometimes referred to as D1. The larger the resolution setting, the larger you are going to be able to view crystal clear video after it has been recorded. When the resolution isn’t set high enough you can look at the picture at a small size and it looks fine, but when you blow it up to full screen it pixelates. You see lots of little squares on the image and the picture gets distorted. When you are looking at 16 camera views on one screen they will all look good, but when you look at a quad with 4 cameras, or just one camera full screen you will really be able to see the difference.
Frames per Second (fps) is the smoothness of the video or more technically how many frames are saved per second from your cameras. 30 fps per camera is the highest you can record for any DVR. If you have a 16 channel system with 480 fps total you divide it by the total # of cameras the system is capable of connecting to. 480/16=30 But if you have 10 cameras connected that doesn’t mean you have 48 fps per camera. 30 is still the max but that doesn’t mean you HAVE to record at the full 30, honestly I normally recommend that you don’t because it just isn’t needed. Even movies are shot at 24fps and you know how good those look. The human eye can’t much tell the different between 20 and 30 fps, so if you record all 30 you are filling up your hard drive a heck of a lot faster and it isn’t helping the quality of your playback. Instances where you need to leave it set at 30 fps is when you are recording license plates and fast moving vehicles or people. Set it too high and it wastes hard drive space, set it too low, your video will look like one of those awful convenience store videos on COPS that makes the vandal look like a critter on Pac Man.
Now most DVRs have counter intuitive functions when it comes to recording settings. Meaning the higher you set one option the lower the other will be altered automatically. This is mostly to help moderate how fast the hard drives fill.
Very high end DVRs have the ability to record at D1 settings. Which would be Full resolution and 30 fps per camera. It fills up the hard drives faster so make sure you have as much internal storage as you can to accommodate the number of days you wish to have stored in case of an incident.
So let’s recap. Your resolution settings will determine how large you can watch your recorded videos, and your fps settings will determine how smooth/choppy your video playback will be.