What is a Camera Iris?
A camera iris is the part of the camera that controls how much light comes through the lens. If the iris creates a larger opening, more light can get through; a smaller opening allows less light through. The light that the iris allows through hits the image sensor and that light gets recorded as electrical impulses that create the video.
When it comes to IP surveillance videos, you have several different styles of camera irises to choose from: a fixed iris, a manual iris, an auto iris, and a P iris.
How a Camera Iris Works
The iris works by limiting the amount of light that hits the image sensor. Too much light can wash out your video, and too little light can make everything dark, so it’s important to have an iris that’s specifically suited for your camera’s location. Each of the four types of camera irises works slightly differently, so you can pick the one that’s best for you.
- On a fixed iris, the opening that allows light into the camera cannot be adjusted
- This type of iris is ideal for indoor recording where the light levels stay consistent when the camera is recording, such as an office or school with many large overhead lights
- With a manual iris, you can adjust the opening to allow more or less light by physically adjusting the iris—this adjustment is typically done during installation when you have easy access to the camera
- This type of iris is typically used in the same way a fixed iris is, because access to a camera after installation can be difficult if it’s installed in a hard-to-reach place
- Auto irises are motorized, allowing them to automatically adjust the iris opening to the changing light throughout the day
- There are two types of auto arises, DC-irises (the control for the motor is in the camera) and video irises (the control is in the lens itself)
- Because auto irises used more advanced technology than a fixed or manual iris, cameras with an auto iris are often more expensive, but better suited to recording in outdoor locations where the changes between sunlight and nighttime can be automatically adjusted for
- The “P” in P iris stands for “precise” because the iris uses both the ability to automatically adjust like an auto iris with controls in the camera’s software to create improved video clarity and depth of field
- The amount that the iris can close is limited, preventing the blurred video that can occur when an auto iris overcorrects for bright lights
- Cameras with a P iris are also more expensive than models with fixed or manual irises, but the cameras are better suited for recording in locations where light is constantly and quickly changing
How Camera Iris Options Can Help You
With four different types of irises to choose from, you can pick the IP camera best suited to your surveillance needs.
Are you recording in an office building, and only during working hours? A fixed or manual iris will work well with the consistent light from overhead lights because they won’t need to adjust to changing light levels.
Recording outdoors or around the clock where your camera needs to adjust to daytime and nighttime light levels, like a parking garage or construction site? An auto iris or P iris will be your best bet, because they are designed to work with constantly changing levels of light.
A variety of camera irises are available in video surveillance systems and IP security cameras from top manufactures including Optica, Axis, and Mobotix.
Learn more with VideoSurveillance.com
With a team of knowledgeable sales and technical support representatives, VideoSurveillance.com can help you learn more about camera iris options and select the iris best suited for your surveillance needs. Call us at (866) 945-6808 or send us a message today!