When you are setting up a camera system, you need to consider two things: the camera lens and an camera sensor. While many person focus on the resolution of the sensor and the night vision of the camera, they often neglect the importance of the camera lens. The camera lens determine the amount of detail that the surveillance camera will show to the viewer.
Using a camera lens that is too wide will make the features on the faces of people that are distant from the surveillance camera to be blurry on the surveillance cameras recorded footage. Using a camera lens that is too narrow for the surveillance cameras field of view will leave certain areas of the monitored area unmonitored by the surveillance camera. People will notice the importance of the camera lens when they are attempting to identify an individual in the recorded surveillance footage, but the lens did not provide enough detail of that individual.
Choose the Right Lens and Sensor for Your Camera
The focal length for a surveillance camera lens determine the field of view of the surveillance camera. The shorter the focal length, the wider the angle of view that the surveillance camera provides. This is useful if you are trying to monitor a large area.
The longer the focal length of the lens, the more narrow the field of view of the surveillance camera. This is useful for surveillance cameras that are installed in location where it is necessary to be able to identify the features of individuals or license plates at a distance. The surveillance camera can also change the field of view depending on the size of the sensor that the surveillance camera use; the smaller the sensor, the more narrow the field of view of the surveillance camera will be.
Before you purchase a surveillance camera system, you should understand the relationship between the lens and the sensor for surveillance cameras. A chart can display the field of view of surveillance cameras with different focal lengths. Another chart can display the field of view of surveillance cameras with different sensor sizes.
To determine the correct focal length for your surveillance camera, you should measure the distances that you would like to be able to monitor. By determining the distances, you can then purchase a surveillance camera that has a focal length for its lens that match the level of detail required for the most distant objects that you would like to monitor with the surveillance camera. Many people make a mistake when purchasing surveillance camera systems because they purchase the surveillance cameras with the wrong type of lens for the purpose of those surveillance cameras.
For example, many people will purchase surveillance cameras with wide-angle lens because they provide wide field of view for the surveillance camera. However, these types of lenses make it difficult for the surveillance camera to clear show the features on the faces of people who are distant from the surveillance camera. Other people will purchase surveillance cameras with long telephoto lenses because they can see objects that are distant from the surveillance camera.
However, the field of view of these lenses is so narrow that they leave large areas of the monitored area unmonitored by the surveillance camera. Different lenses should be used for different purpose. For instance, one lens can be used for a wide-angle lens for monitoring an area for unusual activities, but another lens with a narrow field of view can be purchased for surveillance cameras for monitoring an area where recognition of individuals are necessary.
The type of lens for surveillance cameras can change the flexibility of the surveillance camera after it has been installed in the location. Using fixed focal length lenses for surveillance cameras means that the field of view of the surveillance camera cannot be changed once it is installed. However, if you use lenses that are varifocal, the field of view of the surveillance camera can be changed after installation.
This is useful for surveillance cameras for which the location of the surveillance camera is different than the plan in which the surveillance camera system is to be installed. Using motorized varifocal lenses allows for the field of view of the surveillance camera to be adjusted while the surveillance camera is install in a high or inconvenient location. Certain types of surveillance cameras are used outdoors, or they must have good night vision.
Infrared (IR) surveillance cameras require a lens for surveillance cameras that is able to focus on both visible light and infrared light. If the lens for the surveillance camera is not capable of focusing on both type of light, the footage that the surveillance camera records will be blurry after being recorded during the night. Many lenses that are labeled as being IR corrected are capable of focusing on both visible and infrared light, but many cheap lens will only be able to focus on visible light during the day and the focus on the scene will be blurry at night.
Another thing to consider when purchasing surveillance cameras is that the camera lens should be matched to the resolution of the sensor for the surveillance camera. Using a high-resolution sensor with a low-rated camera lens will not allow the surveillance camera to provide the level of detail that the sensor is capable of capturing. Using digital zoom on the surveillance camera will only blur the images of objects in surveillance camera footage that is recorded with a low-rated camera lens.
To avoid this issue, ensure that the resolution of the lens for the surveillance camera meet the resolution of the sensor for the surveillance camera. By focusing on the purpose for which each surveillance camera is to be used, you can purchase surveillance camera systems that meet those needs. For each surveillance camera, determine what type of focus and detail is required for the objects at the most distant point of the surveillance camera.
By determining the distance and focus requirements for each surveillance camera, you can purchase surveillance cameras with the appropriate focal length and sensor size. By focusing on the purpose of each surveillance camera, you can avoid the mistake that many people make when they do not differentiate between the needs of various surveillance cameras.