First and foremost, the meaning of Varifocal lens is a lens that can zoom in and out. Moreover, these lenses help you adjust the focal-length according to your preferences so that you are not only able to capture the areas extensively but also focus on the details of the smaller areas.
Varifocal lenses come in various aperture sizes varying from 2.8-12mm (being the smallest) to 5-100mm (being the largest). The smallest aperture helps to see the wider areas by zooming out, whereas the largest aperture helps to have a look at the images with more details of the feature by zooming in closer.

A Varifocal surveillance camera offers security installers and integrators, some advantages like flexibility over a fixed-lens security camera. Also, going back to the job site for installing again can cause frustration for both the customer and the installer, plus re-installing a camera costs valuable time and money too. So, it then comes handy as it cut downs on the cost of re-installing.

Following are the reasons why installing varifocal cameras is important.

1) Altering focal length now made easily
The security professionals can now alter and tweak the focal length of the varifocal monitoring devices physically, in order to capture the desired field of view of the customer. Varifocal devices provide the adaptability to adjust the video monitoring devices field of view and it also offers a variation in the focal lengths, without having to re-introduce the cameras again. Moreover, this wipes out the necessity of having to be physically there and re-introduces the camera to conform focal-length.
This is particularly gainful for clients who alter their opinion as often as possible. For instance, sometimes a customer demands a particular focal length, then later seeing the live picture caught inside the field-of-view, chooses they need the camera to catch an alternate edge or view.

2) Trouble-free installation
There are some varifocal monitoring devices that feature motorized lenses. These have the ability to mechanically adjust the zoom and focus of the monitoring device. This way they make the installation simple, as it automatically focuses by removing any chance of the focus errors.
Plus, if the lens is motorized, then the changes in the field of view (if required) can be made on the fly by using the camera remotely.

3) Better outdoor security with special lens
The auto-iris is the lens that in the varifocal security cameras makes the cameras well-suited for capturing outdoor scenes especially when the lighting conditions are varying.
Also, auto-iris lenses are more high-tech than fixed iris lenses. They are powerful in nature, which lets a varifocal-camera to automatically alter the opening of the iris in the surveillance camera, in order to adapt to uncertain lighting conditions throughout the day and night.

4) More than cost effective
In case of fixed lens camera, if after some time you change your mind and want to view from a different angle, then that is the time when you need to reconsider and reinstall it in order to change its location. The process of reinstalling the monitoring device involves costs of wiring, changing the location, drilling, and other inclusive costs. This all costs you extra time, money and energy in the long run. A varifocal lens security camera helps clear the headache of frequent reinstallation. If the camera has Wi-Fi or PoE enabled, the installation process then becomes much easier.
These lenses can prove helpful in the long-run by offering the flexibility of changing the focal length at a present or future time that also without having to physically remove the camera from the wall or ceiling and re-installing the monitoring device to capture the desired focal length. Hence, becoming more than just being cost-effective.

5) Resilient installation
When you choose varifocal monitoring device over fixed lens security camera then the chances of resilient installation increases. In case the location requirement changes it then gives you an opportunity or flexibility to easily customize the focal length.

That’s all from my side. If there are any other benefits of these lenses which you feel are important and I skipped, feel free to mention them in the comment section.

Author's Bio: 

Ted Yu is a gadget wizard, an active blogger, and an eminent speaker. With more than 10 years of experience to his credit, Ted has always been a pertinent contributor to the security industry. He is closely associated with Revo America, a well-renowned security products manufacturer and retailer. Needless to say, Ted boasts of paramount and credible products only, with Revo's being his favorite.