Security cameras are able to use two main types of lenses to focus on the parameters of their recording. It could be a fixed lens or a varifocal lens. The fixed lenses have a consistent and unchangeable length of focus, where the varifocal lenses have a length that can vary substantially. Some people have heard the varifocal lens referred to as a zoom lens, which is the purpose of the following information.
Beyond just the lens itself, you also have to consider what your lighting requirements are going to be. The iris is normally the brains behind the amount of light that is allowed to come through the lens and into the sensor chip. It could be a fixed, manual or automatic iris on the lens. This whole process controls how the iris is able to make the light flow, which controls how small or large the aperture is going to be. It is the equivalent of the pupil in the human eyeball. If you are in a low lighting situation, you will want the aperture to be wide open to help promote enough light in to be able to power up the sensor chip inside. However, in a bright lighting condition, the aperture is too minute to prevent ample lighting from flooding out the sensor chip.
If you are using the security camera inside with a consistent light source, a fixed iris lens will be able to serve the purpose you need it for. However, the actual viewing range may need to adjust the shot to tighten it up, which is where a varifocal camera can be the key to it all. Settings that have lighting conditions that vary will require an auto iris lens to help compensate for all of the differences in lighting levels. Lighting situations that remain constant for extended periods of time but change between dark and light can use a manual iris lens. These particular lenses are changed y hand to help provide you with the optimal lighting conditions.
A lens is developed using a combination of different varifocal and fixed parameters along with the help of a fixed, manual or automatic iris aperture. The vast majority of security cameras have a focal length of between 3.6 mm and 16 mm for a fixed lens, but a varifocal lens will have a length of greater than 70 mm. Shorter focal lengths will provide you with a larger viewing area; whereas, a longer length will provide you with a narrower field of view.
Varifocal cameras are extremely easy to use and versatile for all of your needs. There are multiple forms of varifocal cameras, just like there are a lot of different types of irises for the cameras. Some of these cameras are manual, which means that you are going to have to physically go out and change the length of the camera. Other types are automatic and they can be changed with a simple control that is connected with the digital video 
recorder.
The key is determining whether or not you are going to need a varifocal camera or not. Cameras that are located at the end of a straight, long driveway are the perfect places for varifocal cameras. You can zoom in on the objects in the driveway, as well as those coming in and out of it and still keep everything in focus. On the other hand, consider a camera that is pointing in the direction of the doorway to help monitor movement around the door. You would not need to have a varifocal camera in place, but a fixed lens would serve the purpose just fine.
If you are searching for a digital security camera that will provide you with a tight shot, you might want to invest in a varifocal bullet camera. This particular type of camera is reasonably priced, yet it will still provide you with the high definition picture that you have been looking for. Unless you have purchased a camera that is vandal proof, you need to make sure that it is located out of sight. The nature of this type of camera makes it vulnerable to an attack from an intruder, so keeping them hidden out of view is critical.
Before you make any major purchases, you need to determine if a bullet camera is the right choice for your specific needs. Beyond just that, you need to decide if a varifocal bullet camera is going to handle your specific application. Understanding the camera lens and how it works will help provide you with the necessary knowledge to be able to make an intelligent decision when purchasing you camera.
To begin, let’s talk about the three different types of cameras. Based upon their shape, they are the dome, the box and the bullet type camera. Dome cameras tend to be used mainly inside or outside of the property. Typically, you will find them mounted to the wall or a ceiling. Their bubble design makes them less bulky than that of their box and bullet counterparts. The vandal proof dome cameras are constructed from steel with a Lexan sphere for the camera to be able to view everything in the room.
Box cameras tend to be the most popular of all the cameras on the market today. Unlike the bullet and dome cameras, the box camera is normally sold as a basic camera with no lenses, additional hardware and no weatherproofing to name a few of the features they are lacking. You will need to purchase all of the components that you need for your specific situation separately, which in the end helps to make these cameras very flexible in what they are able to do.
As time goes by, the bullet cameras are becoming more and more popular. They come equipped with a variety of features right from the beginning that makes them versatile in nature. Normally, they come built with weatherproofing technology and nighttime infrared features to provide them with some of the best advantages around.
However, the varifocal bullet cameras come with their share of disadvantages. Due to the way they have to be mounted, it can be extremely difficult to make them resistant to vandalism. If this is not something that you are worried about, the bullet camera can be one of the best options for your new digital security system.
The responsibility of the camera lens lies within one main function. It is meant to gather the light that is reflected onto objects in the field of view. The sensor chips range of viewing is between ¼ to ½ inches. These lenses may be fixed or varifocal to avoid a lot of technical issues when it comes to the different types of lenses.
Fixed lenses have a specific viewing range, which may be broad or tight depending on what type of lens you are using. A lot of times the fixed lenses are not able to be replaced because they are a vital component in the way the bullet cameras work, hence the reason why they are referred to as board lenses. The only way you can change your viewing range is to use another type of lens with these cameras, if the bullet camera is compatible for that change to occur. However, since the vast majority of these cameras use board lenses, they are not able to be changed out.
One of the best solutions to a fixed lens is to use a varifocal one. While fixed lenses only offer one length, the varifocal cameras can provide you with a variety of focal lengths. The range can be as extensive as 3.8 mm all the way up to 100 mm. That is quite a large viewing range when it comes to one camera lens.
What exactly does all of this mean when you think about the range and length of the camera lens? Generally, the shorter the length of focus the wider shot you are going to receive. Essentially the 3.8 mm lens will produce the widest angle possible. When you think about the longer focal lengths, you will notice that their viewing angle is extremely small. Lenses with 100 mm focal lengths will produce the tightest camera shot available. Another way you could think about it is to imagine the varifocal bullet cameras as that of a zoom lens. The larger the maximum amount is on the lens, the higher the zoom capability will be.
If you take a bullet camera and add an adjustable lens onto it, you will be able to term it a varifocal bullet camera. This particular type of technology comes equipped with the infrared features built right into the camera. There is a lot of information when it comes to choosing the right camera for all of your needs, but we are here to help you along the way. Anytime you have questions that need answering we will we standing by to help you in any way possible. For your entire security camera needs let us be the ones to help make the decision that much easier for you.