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When we talk about picture quality, you will often hear the term “megapixel” when discussing the overall quality of a camera.
However, megapixels alone aren’t the only thing that determines the quality of a photo or video. In fact, you’d be surprised by how much detail you can get with just a 4-megapixel camera!
CCTV cameras come in various configurations. Some CCTVs offer 2-megapixel quality to up to 24 megapixels. Most people think that getting a higher megapixel count would be better, but they could be very wrong.
Read on to learn more about CCTV resolution myths and why more megapixels aren’t always better:
THE BIGGER THE BETTER?
Megapixels are highlighted in almost every marketing material for cameras. In the world of security footage, you would often see the megapixel count in big bold text and highlighted on every side of the box when buying a new CCTV camera.
However, the truth is that megapixels aren’t the only thing that matters. There are, in fact, three other factors:
- Lens Quality
- Sensor Size
- External Conditions
Lens Quality
People who are not well-versed in photography technology might not know the impact of lens quality in cameras. Many people may think of the lens as a protective barrier, but a camera’s sensor can only capture as much detail as the lens allows it.
If the lens is low quality and refracts incoming light haphazardly or disperses it too much, then you will never get a good quality photo or video out of your CCTV system, no matter how many megapixels the camera has.
Sensor Size
The camera sensor is what takes in the light and processes it to create a crisp photo. The focal length and sensor size are perhaps two of the most important figures in a camera spec sheet.
A larger sensor with an appropriately sized lens can massively boost the photo or video quality of the CCTV system, even if you have a 4-megapixel camera.
With this strong combination, you can get crisp and highly detailed footage with a smaller file size, which can end up saving storage and reducing costs.
This is partly why many companies, like Apple and Samsung, had initially settled on a 12-megapixel camera for their early smartphones, because it offered the best ratio between cost, storage, and quality.
Here’s an interesting fact: if you increase the megapixels on the same sensor size, the pixels will end up becoming smaller and collect less light, which would produce low-quality footage, especially during nighttime.
In this case, an increased megapixel count will result in a grainy or noisy image at night, which would defeat the purpose of the CCTV.
For example, a 4-megapixel camera with a large sensor would be able to produce clear night footage, whereas a cheaper 8-megapixel camera with a small sensor would produce almost unusable images at night.
External Conditions
Apart from the camera lens and the sensor size, there are also several external factors that play a role in the quality of the security footage, regardless of the megapixel count.
There are three core external factors:
Lighting
Adequate lighting is key to obtaining good quality and highly detailed security footage. However, there should always be a good balance when lighting an area for a CCTV camera.
Too much light can cause lens glare and result in unusable footage, whereas too little light can cause grainy or noisy footage, which is also unusable.
The CCTV should point away from the light source, and the lighting should be done in a way that illuminates all corners of the area adequately. This way, you can get crisp and highly detailed footage with even a 4-megapixel camera.
Camera Placement
Where and how the CCTV cameras are placed also play a huge role in the overall footage quality. For example, a camera placed on a pole that sways with the wind will not obtain highly detailed footage.
Similarly, a camera placed in the direction of the sun or any other significant light source will also result in bad-quality footage. Most professional installers, like Calder Security, use industry-standard best practices to determine the best layout for the installation of CCTV cameras.
This is why we recommend that you get your CCTV system installed professionally instead of going the DIY route to save a few bucks.
Dust/Debris
One of the most common things that causes a dip in the footage quality of CCTV cameras is dust.
You would be surprised by how much a layer of dust can mess with the lens and focus of the camera. With even a thin layer of dust, your camera might record blurry footage, even if it has a higher megapixel count.
We recommend that you regularly keep your CCTV system maintained by a professional security company that can send out technicians to service your system.
WHEN DO MEGAPIXELS COUNT?
In most cases, megapixels come in handy when you want to print a high-quality photo or if you want to retain high-quality details when cropping into a photo or video.
Typically, a 4-megapixel camera is more than enough to obtain high-quality footage of people’s faces, vehicle plate numbers, and more. However, if you want to have even more detail, then you can go with an 8-megapixel or higher camera.
These cameras offer 4K recording capabilities, which provide an excellent level of detail and can be useful for businesses or residential users who want to zoom in on details around their premises.
For example, a higher megapixel count camera over an area that deals in cash can be useful since you can zoom in and clearly see the paper currency being exchanged.
So, a high megapixel count camera is a nice-to-have feature that everyone should invest in? Not really!
The truth is, you can get by with a simple 4-megapixel camera that balances quality and cost. By going with higher resolution cameras, you will surely increase the quality of the footage, but also the cost of storage.
A simple 4 MP footage will be much “lighter” and take just a few megabytes compared to 4K footage that can go up to several hundred megabytes. In other words, you will need to increase your storage capacity and therefore incur higher costs over time, especially if you plan on keeping the footage for longer periods.
Ideally, you should keep the footage for no more than a maximum of 30-31 days. This is the standard retention period for businesses, while home users must aim to keep footage for around 7-14 days.
With a bigger megapixel CCTV camera, you will have to invest hundreds of pounds in an adequate storage system. This is why we recommend that you go with a 4-to-8-megapixel camera and opt for ideal installation and placement best practices to maximise footage quality.
CAN YOU GET BY WITH A 2 MEGAPIXEL CAMERA?
You might think that a 2-megapixel camera might not cut it for recording basic CCTV footage, but you would be surprised by the level of quality you can get with this camera if it is installed properly.
The only downside is that this camera will be great for capturing details at a close range, but if you want to capture minor details like the licence plate of a nearby car, then you would just get a blurry blob when zooming in.
A 2-megapixel is still 2 million pixels! That’s a lot. So, if you have a limited budget and only want a simple point-and-shoot camera for the front door or side alley, then this camera would suffice.
However, if your budget allows for it, then we recommend always opting for at least a 4-megapixel camera for better futureproofing. Both 2- and 4-megapixel cameras will record in 1080p quality, but the 4-megapixel camera will provide a great balance between cost and quality since you will also be able to zoom in a bit on the footage for more detail.
Here is what you should keep in mind when choosing between a low and high megapixel count camera:
- For simple home monitoring (rooms, front/back door, etc.), a 2-to-4-megapixel camera is more than sufficient.
- For monitoring large areas like carparks, an 8-megapixel or higher camera is typically recommended since it can capture licence plates and faces better.
- For cameras covering large spaces, we recommend getting a 4K camera, especially if you want to cover more area with fewer cameras. However, you will also have to bear the added storage cost for the footage.
- If you want zoom capabilities for small to medium-sized areas, then go with a 4-to-8-megapixel camera for better quality.
GUIDELINES TO FOLLOW FOR BETTER CCTV FOOTAGE
Let’s explore some of the finer details of how you can get a crisp quality footage from your CCTV camera.
This guide will cover the best practices for both smaller and bigger megapixel count cameras.
Lens, Sensor and Compression
When inspecting the box of the camera that you intend to buy, we recommend that you make sure that you carefully look at the focal length and the sensor size of the camera.
Generally, you should go with a camera that offers a decent focal length of around 20 to 35mm for better zoom capabilities. Additionally, we recommend a shorter aperture (1/8 vs ¼) since it allows for a wider shot and lets in more light for the sensor.
For the sensor size, typically, CCTV cameras come with a sensor size of 1/3″ to 1/1.8″, with larger sensors like 1/1.8″, 1/2.8″ providing better low-light performance, wider field of view, and higher image quality.
The compression is done on the software end, which is why you should look at the spec sheet and search for how the video is encoded. A video that is heavily compressed will provide lower quality, even with a high megapixel count.
Higher compression is done to save storage, but usually at the cost of the quality. However, reputable companies use advanced compression algorithms to maintain quality and keep the footage within a reasonable file size.
If all of this seems too technical for you, then we recommend that you leave all these technical aspects of sourcing the right camera to professionals. This is partly one of the reasons why DIY projects for CCTV cameras end in disaster and a waste of money!
Camera Height
The optimum height for installation plays a major role in how well the cameras will be able to view and record.
When placed too low, the CCTV cameras will obtain a sharper image, but you wouldn’t be able to get the most out of the camera since it will be able to capture a wider view when placed at a suitable height.
If the cameras are mounted too high or far away, the footage may turn out pixelated and grainy, which may make it difficult to identify faces and other details. This is especially true for lower megapixel cameras.
Typically, an installation height of around 2.5 to 5 meters is the most common, although it depends on the area in which the cameras are being installed.
2.5 meters is a good height for close-up views with better quality footage, whereas 5 meters is a better option for higher megapixel count cameras that are placed in areas that require wide-angle surveillance.
Angle of the Camera
CCTV cameras placed at the wrong angle won’t be able to capture the required footage, and even with a higher megapixel count camera, you will have useless footage.
This is where professional installation comes in.
CCTV cameras are always installed at carefully selected strategic locations, with the lens usually angled downwards instead of at a steeper angle.
You would rarely see a camera placed at eye level, with most of them placed at a high vantage point for a better and wider field of view. Another important point to consider is that the cameras are angled in a way that they are placed away from light sources.
If the camera is angled near a light source, then the lens will pick up on artefacts that may make the footage unusable. The best way to go about this problem is to let professionals assess your premises and give you a layout for your CCTV camera system.
You can also work with the security team and share your expectations with them so that you can get a highly personalised layout that is specifically built to address the blind spots in your premises.
CONTACT CALDER SECURITY
At Calder Security, we offer a comprehensive solution for CCTV cameras that are state-of-the-art and comply with CCTV laws and regulations.
We understand the special security and safety needs of various properties and offer professional installation services for CCTV systems bespoke to each property.
We are expert SSAIB-approved security system installers and supply only high-quality CCTV equipment from trusted brands such as Hikvision, one of the world’s leading CCTV manufacturers.
We conduct every aspect from surveys, design, specification, and installation ourselves, and our professional repair and maintenance services ensure that the CCTV systems work in optimal condition all year round, guaranteeing effectiveness and compliance with the law.
We also offer professional CCTV monitoring services that help detect criminal activity and security breaches as they are in progress, for the appropriate action to be taken, even when the property is empty.
Contact us here or call us at 0800 612 9799 to talk to our security experts for more information on CCTV resolution and why more megapixels aren’t always better.
Photo by Tasha Kostyuk on Unsplash