Regarding Plates:
Your thinking is wrong LOL.
Shutter speed is more important than FPS. I capture plates at 8FPS and the plate is in and out of the field of view in about a half second (so I capture 4 frames) because I am using the correct shutter speed for the task at hand.
I will take a camera at 10FPS with a properly dialed in shutter for the speed of the object I am trying to capture over 60FPS with a camera on default/auto settings all night long.
You would have to set the camera up specifically to read plates. You need the proper camera with OPTICAL zoom for the distance you are covering and the angle to get plates.
Keep in mind that this is a
camera dedicated to plates and not an overview camera also. It is as much an art as it is a science.
You will need two cameras minimum. For LPR we need to OPTICALLY zoom in tight to make the plate as large as possible. For most of us, all you see is the not much more than a vehicle in the entire frame. Now maybe in the right location during the day it might be able to see some other things, but not at night.
At night, we have to run a very fast shutter speed (1/2,000) and in B/W with IR and the image will be black. All you will see are head/tail lights and the plate. Some people can get away with color if they have enough street lights, but most of us cannot. Here is a representative sample of plates I get at night of vehicles traveling about 45MPH at 175 feet from my 2MP 5241-Z12E camera (that is all that is needed for plates):
See the
LPR subforum for more details.
Regarding FPS
These types of cameras are not GoPro or Hollywood type cameras that offer slow-mo capabilities and other features. Some "offer" 30FPS and 60FPS to appease the general public that thinks that is what they need, but you will not find many of us here running more than 15 FPS; and movies are shot at 24 FPS, so anything above that is a waste of storage space for what these cameras are used for. If 24 FPS works for the big screen, I think 15 FPS is more than enough for phones and tablets and most monitors LOL. Many of my cameras are running at 12FPS.
Sure 30FPS can provide a smoother video but no police officer has said "wow that person really is running smooth". They want the ability to freeze frame and get a clean image. So be it if the video is a little choppy....and at 10-15FPS it won't be appreciable. My neighbor runs his at 30FPS, so the person or car goes by looking smooth, but it is a blur when trying to freeze frame it because the camera can't keep up. Meanwhile my camera at 15FPS with the proper shutter speed gets the clean shots.
We wouldn't take these cameras to an NBA game to broadcast, nor would we take the cameras they use at an NBA game to put on a house. Not all cameras are alike and the approach of "a camera is a camera" mentality will result in failure. Another example, I can watch an MLB game and they can slow it down to see the stitching on the baseball. Surveillance cams are not capable of that. You need to find a camera for the intended purpose.
Watch these, for most of us, it isn't annoying until below 10FPS
Regarding Substreams
Substreams typically reduce CPU usage by 5x to 20x and make a struggling system run great. The full quality main stream is still recorded and available when you need it.
When you configure a camera in
Blue Iris to use a sub stream, Blue Iris will pull video from both the "main" and "sub" streams. Each stream is used for different purposes.
The main stream is used for:
- direct-to-disc recording
- single-camera live viewing and recording playback
- audio
The sub stream is used for everything else:
- multiple-camera viewing
- motion detection
- alert snapshots
- etc.
The NOOB always comes here worried about video quality and missing something using substreams.
We are a bunch of security sensitive people and if substreams resulted in missing a key action, we wouldn't be using it.
That is the beauty of the substreams, you can do whatever you want.
Record continuous and it will record mainstream 24/7 but use the substreams for the CPU intensive features.
Record continuous plus triggers and it will record substream until a trigger and then go to mainstream - you can set the triggers pretty low so that it records for anything.
Record continuous plus alerts and it will record substream until an alert and then go to mainstream - with this one you run the risk of missing a trigger than wasn't elevated to alert level.
But if you do anything other than continuous it will result in disc space savings.
The biggest problem people make is trying to do too much with one camera. Using a 2.8mm fixed lens to try to IDENTIFY or capture motion at 50 feet is the wrong camera. Which leads to:
Camera Selection
You need to get the correct camera for the area trying to be covered. A wide angle 2.8mm to IDENTIFY someone 40 feet away is the wrong camera regardless of how good the camera is. A 2.8mm camera to IDENTIFY someone within 10 feet is a good choice OR it is an overview camera to see something happened but not be able to identify who.
One camera cannot be the be all, see all. Each one is selected for covering a specific area. Most of us here have different brands and types, from fixed cams, to varifocals, to PTZs, each one selected for it's primary purpose and to utilize the strength of that particular camera.
See this thread for the commonly recommended cameras (along with Amazon links) based on distance to IDENTIFY that represent the overall best value in terms of price and performance day and night.
The Importance of Focal Length over MP in camera selection
