Navigation
- Fixed Lens Security Cameras and Zoom Lens Security Cameras
- How effective are different focal lengths for wide-angle security cameras?
- Zoom lens
- What focal length should you use?
- Conclusion
Home security cameras are a popular choice for protecting your home and keeping an eye on your property. But with so many options for placement, it can be difficult to decide where to place your cameras. In this blog post, we will explore some of the key factors to consider when deciding where to place your home security cameras, as well as some general guidelines for getting the best coverage. Whether you are installing a single camera or a full security system, this guide will help you make informed decisions about where to place your cameras for maximum effectiveness.
Fixed Lens Security Cameras and Zoom Lens Security Cameras
The focal length, or the size of the security camera lens, is the main factor that determines the field of view. A camera with a larger lens size results in a narrower field of view and shorter viewing distance. Conversely, cameras with smaller lens sizes, also known as wide-angle security cameras, produce a wider field of view and a longer viewing distance. Usually, the lens of the surveillance camera does not need to be adjusted by ourselves, which we call a fixed-lens security camera. Fixed-lens camera lenses do not allow adjustments in focus, angle of view, and zoom level, and almost all fixed-lens cameras are wide-angle cameras. A zoom lens camera is a camera lens with a variable focal length that changes as the focal length changes. Typically, zoom security cameras have a focal length of 2.8 to 12 mm, which you can adjust to increase and decrease the field of view as needed.
What is focal length?
(F is the focal point and f is the focal length. Different lenses focus light at different focal points and therefore have different focal lengths.)
Focal length, also known as focal length, is a measure of the concentration or divergence of light in an optical system and refers to the distance from the center of the lens to the focus of light concentration. It is also the distance from the optical center of the lens to the film, CCD, or CMOS imaging plane in the camera.
How effective are different focal lengths for wide-angle security cameras?
Ordinary surveillance cameras often provide lens indicators of different specifications such as 3.6mm, 4mm, 6mm, 8mm, and 12mm. So what's the difference between different focal lengths? Let's take a look at the common sense of security camera lenses today.
Summarize:
The larger the focal length, the smaller the viewing angle and the farther you can see.
The smaller the focal length, the larger the viewing angle range and the closer you can see.
A focal length effect comparison chart for reference:
As shown in the picture:
At the same distance (such as the first column), the larger the focal length, the smaller the viewing angle range, but the clearer the relative details.
Under the same focal length (such as the first row), the farther the distance is, the wider the range of viewing angles can be seen, but the lower the recognition degree.
If you want to see a human face or human figure clearly, the farther the distance is, the greater the focal length you need.
Zoom lens
Zoom lenses allow the user to manually adjust the camera focal length, angle of view, and zoom level. The general sizes of lenses are 2.8-12mm, 3.5-8mm, 6-60, and 5-100mm lenses. The larger the f-stop, the more the image is magnified and the more details can be captured, but the field of view will be smaller and therefore the image will be narrower. The smaller the f-stop, the wider the field of view, but the less detail is captured. If you need to precisely adjust the monitoring angle and field of view, it is recommended to use a security camera with a zoom lens so that you can adjust the lens to the exact view you need.
What focal length should you use?
Monitoring scope
One of the most important considerations when choosing a wide-angle security camera for your home or business is knowing how much area you need to monitor. Therefore, when looking for a surveillance camera, the field of view (viewing angle) of the surveillance camera must be considered. A security camera's field of view, also known as the field of view, is the area the camera can see. The focal length of the monitoring camera determines the size of the monitoring screen and the effective viewing distance, that is, the monitoring range.
- For scenes with a small monitoring range but large angles, such as family living rooms, small shops, etc. You can choose a surveillance camera with a smaller focal length. For example, with a camera with a focal length of 3.6mm or 4mm, the viewing angle range can reach 75°-90°, the effective monitoring distance can reach more than 5 meters, and it can cover a space of 40-80 square meters. Such as Campark SC03 4MP 100% Wire-Free Wireless Security Camera System.
- For a larger monitoring range, such as a space above 10m*10m, it is necessary to choose a monitoring camera with a larger focal length. However, due to the large focal length, the corresponding surveillance angle will become smaller. To achieve complete surveillance, you can consider using PTZ security cameras, or installing multiple surveillance cameras to ensure complete coverage. Such as Campark SC09 4MP Wireless 10x Hybrid Zoom 360° PTZ Outdoor Security Camera.
- For situations where the monitoring range is fixed but the distance is very far away, for example, it is necessary to monitor a parking space 30 meters away, it is necessary to choose a camera with a larger focal length, such as a surveillance camera above 12mm.
Scenes to be used
In many cases, surveillance cameras are selected for specific scene requirements. If you don't want to know too much about those cumbersome focal length parameters, we can roughly judge and choose the focal length of the camera according to the following usage scenarios:
- For narrow spaces such as garages and storage rooms, it is recommended to choose a focal length of 2.8mm, and the best monitoring distance is within 3m.
- For home indoor monitoring or small shops, etc., it is recommended to choose a focal length of 4mm, and the best monitoring distance is 3-5m.
- For home courtyards, balconies, doorways, and other places, it is recommended to choose a focal length of 6mm, and the best monitoring distance is 5-10m.
- For outdoor monitoring such as roads, alleys, etc., it is recommended to choose a focal length of 8mm, and the best monitoring distance is 10-20m.
- For some long-distance fixed location monitoring, it is recommended to choose a focal length of 12mm, and the closest monitoring distance is about 20-30 meters.
Conclusion
After reading the above content, I believe you should also have a basic understanding of the focal length selection of surveillance cameras. However, in choosing a surveillance camera, in addition to the focal length, multiple factors such as camera resolution, night vision function, power supply network, and smart functions must be considered comprehensively to find the most suitable model for you. If you have any questions about security cameras, please feel free to contact Campark, and Campark will solve your questions for you as soon as possible.