Choosing the right security camera is key to achieving reliable surveillance. One of the most important decisions you’ll make is whether to use a varifocal lens or a fixed lens camera. While both capture high-quality video footage, they differ in flexibility, installation options, and field of view. Understanding how these two lens types work can help you select the best camera for your security needs.
What is a Varifocal Lens Camera?
A varifocal lens is a security camera lens with an adjustable focal length, angle of view and level of zoom. This type of lens is often used in facilities like airports, hospitals, government offices and warehouses.
Varifocal lenses allow you to find the perfect field of view, so you can cover as much ground as you need with your camera. Varifocal lens security cameras offer a to-and-from range, which can usually cover around 2.7 and 12mm. Some can even cover long-distance surveillance like license plate recognition, covering around 4.5 to 60mm.
There are various varifocal lens security cameras available: varifocal IP cameras, varifocal bullet cameras and motorized varifocal lenses.
When to use a varifocal camera
If you don’t know the exact field of view required
It can be difficult to envision the exact field of view you require in a site. This is what makes a varifocal ideal – you can adjust the lens to get the desired view. For example, if your camera is mounted at a distance from your subject, a fixed lens may include unnecessary detail. By adjusting the lens, varifocal cameras ensure your field of view only includes the subject you’re interested in.
Long term flexibility
If your use of a system changes over time, then a varifocal camera can adapt to your business needs. For example, if you start off needing an overview, then later wish to focus on a specific area, you can do so with an adjustment.
Sharper image quality
When you’re adjusting the varifocal field of view, you can manually set the viewing angle and depth of field. This enables you to monitor a specific of interest area within a scene.
If you’re trying to do the same with a static camera you need to use the digital zoom, however the image quality may be reduced. This is because digital zoom enlarges the original image, using less pixels to give you the view you require.
With a varifocal camera, you adjust the lens to focus on the area of interest. This, therefore, allows you to utilize the full resolution of the camera, producing a high-quality image.
What is a fixed lens security camera?
As the name implies, a fixed lens camera comes with a pre-configured lens that gives you a fixed field of view. A fixed lens camera usually comes with only a few moving parts, making its installation easy and quick. However, when it comes to reinstallation, fixed cameras require a lot of work. Unlike varifocal lenses that you can adjust after installation, you must remove and reinstall this type of camera to get the correct field of view.
Apart from its simplicity, fixed lens cameras are also affordable, which makes them popular for small businesses and adding additional security to larger systems. Fixed lens security cameras are also an excellent tool for general protection in a wide variety of applications.
When to use a fixed-view camera
You have a strict budget
If you don’t have a big budget for physical security equipment, fixed view lens cameras are a good option. Many factors can affect the price of physical security equipment. However, fixed lens cameras usually cost less per unit than varifocal lens cameras. Installation fees also depend on a variety of factors, but since fixed cameras don’t have a lot of moving parts, they tend to have lower cost.
When you are happy with an overview
If you know the specific areas you want to cover, fixed view models are a great choice. This makes it an ideal option for small businesses and small spaces that don’t need to cover a complicated field of view. For instance, a small retail store that only needs to monitor areas like the register, storage room and entrances or exits can benefit from using this type of security camera.
Quick and easy install
Fixed lens security cameras don’t typically come with many moving parts, making installation very straightforward. Additionally, once the bullet or dome camera is manually set in place by a security installer, you don’t have to worry about making any adjustments to the viewing angle. This relative simplicity is why many smaller facilities and businesses opt for a fixed lens camera as their indoor and outdoor security cameras.
Conclusion
Both varifocal and fixed lens security cameras serve essential roles in surveillance systems. Fixed lens cameras are affordable and easy to install, while varifocal cameras provide flexibility and precision. Understanding their differences allows you to choose the right camera type for your security goals—ensuring clear, reliable footage and better protection of your premises.
