How to use the manual zoom in a varifocal security camera? It’s pretty easy and straightforward but it requires a bit of practice to get the picture right. In this guide, we will explain how the varifocal cameras work and how to zoom and focus.
As you may know, most CCTV security cameras come with a fixed lens that doesn’t allow any zoom function. The camera is focused on the manufacturing line and all you have to do is install it. The view angle in these cameras depends on the lens size. For example, a 2.8mm fixed lens camera has a wider angle (110 degrees) when compared to a 4 mm camera (90 degrees).
On the other hand, varifocal security cameras come with an adjustable lens that can be modified depending on the installation job. There are two types of varifocal cameras: motorized ones that can be adjusted via the recorder and manual zoom which we will cover here.
A manual varifocal camera is a camera that can be zoomed in and out, as well as focused manually. For example, a popular varifocal camera has a lens of 2.8-12mm which means it can go from a wide-angle (2.8mm) to a very narrow one (12 mm).
Keep in mind, varifocal cameras are not PTZ cameras, their main purpose is to facilitate the installation process and provide you an option to calibrate the camera to the correct viewing angle. Then once the adjustment is finalized, the picture will stay fixed.
How to Zoom in Varifocal Security Cameras
Varifocal security cameras come with two parts that can be adjusted: the zoom and the focus. First, you can zoom in or out and focus on the picture until it is sharp and clear.
There are a few ways you can check the live picture of the varifocal camera that you’re trying to use. You can hook up the camera to a recorder and then check the picture on the monitor. Additionally, you can connect the phone to the recorder and see the cameras on the phone, then when you get up the ladder simply bring out your phone and check the live image.
Another technique involves using a handheld test monitor which is generally used by professional installers. However, we think it’s not necessary to get a test monitor since you can view the camera via your smartphone.
WARNING: Do not force the zoom or focus screws as they can break. If you find it hard to turn, most likely the screws are already at the end of their turning ranges. Any damage will void the warranty.
Instructions to adjust a varifocal security camera
Find the zoom and focus screws located on the bottom side of the camera. While watching the live view on the monitor or phone, use your allen/regular screwdriver to slowly turn the zoom gear.
Depending on which way you turn the screw, you’ll see the pictures zooming in or out. As it zooms slowly, the picture will start to blur (you need to focus with the other screw to clear it up).
Turn the other screw that is labeled “Focus” until the picture on the screen is sharp and clear. Turn it slowly and repeat until the image makes you happy.
Some cameras can be focused if you zoom all the way. This depends on the quality of the camera, we have noticed that most varifocal cameras on the market are not able to focus when the lens is to the max or to the minimum. So, if you can’t focus, zoom in or out a little bit and try to focus again.
The Focus adjustment is very sensitive, you need to do extremely slight turning to achieve a sharp image. If you went too far, then turn it slightly back.
From our experience, it’s better to start to focus the camera and then start zooming in or out. If you zoom too much, it will get too blurry to see anything on the screen. The rules listed here apply to almost all manual zoom varifocal cameras regardless of their brand or type.