Differences in Camera Resolutions
Many people use camera without knowing its standard. When generally integrators use 2MP or 1.3MP Camera every installation they do. We at Global e Solutions thinks differently. Each and every situation is unique. And each situation need Cameras to match its real requirements. No need to compromise the situation to fit available Cameras to use in different situation. We should make available cameras that matches the situation.
One of the most important and desired aspects of a camera is the resolution it can offer. A camera’s resolution is vital for providing usable images capable of identifying people and number plates. A long-standing advantage of using an IP camera over an analogue camera has always been the ability to provide a much higher resolution than a typical analogue camera, although the gap is now being closed by HD analogue solutions.
Resolution is measured in pixels, and is often abbreviated to Megapixels or MP. One megapixel (1MP) is equivalent to one million pixels. Thanks to advancements in technology and the subsequent drop in prices, currently we like to begin all of our conversations at 4MP – Many IP Camera Manufacturers now shipping cameras from 2MP to 12 MP. 12MP Price is very high and cannot use in normal conations at its premium price, but it will down in few years. for example, 4MP are now priced lower than what a 2MP camera would have cost you a couple of years ago.
For the most part, a higher resolution is always preferable. There are a few caveats however, as a higher resolution video stream will require greater storage and bandwidth headroom for example, and typically low-light performance will begin to suffer. However, the quality of images will dramatically improve as you increase the resolution; a face or number plate will contain a greater number of pixels-per-foot, allowing finer details to be picked out and recognized.
Below is a list of common IP camera resolutions and their respective pixel Width x Height measurements based on a IP camera available in market, You may be familiar with certain resolutions when you consider your TV or PC monitors.
1MP = 1280 x 720 (720p)
1.3MP = 1280 x 1024
2MP = 1920 x 1080 (1080p)
3MP = 2048 x 1536
4MP = 2688 x 1520
6MP = 3072 x 2048
8MP = 3840 x 2160 (4K / UHD)
Many of our customers aren’t aware that a 4MP camera actually provides a significantly higher number of pixels (double, in fact) than the 1080p TV and monitor they’re typically used to dealing with. This is further compounded by the fact that most cameras will automatically resize their stream display in order to fit on a monitor that doesn’t support the camera’s resolution – you wouldn’t be able to view the entire 2688 x 1520 stream on a monitor only capable of outputting 1920 x 1080 for example. It is almost always possible to view the stream at its native resolution, but you’d have to scroll around to view the entire image as some of it will be off-screen. The true benefit is seen when zooming in on a distant item of interest.
1MP (1280 x 720) – 4mm focal length
2MP (1920 x 1080) – 4mm focal length
3MP (2048 x 1536) – 4mm focal length
4MP (2688 x 1520) – 4mm focal length
8MP (4096 x 2160) –
Images Overlaid to Show Relative Size
1MP = Green
2MP = Cyan
3MP = Blue
4MP = Yellow
8MP = Red
Further resolutions will follow shortly.
It’s important you also consider what focal length you’ll require when purchasing an IP camera. Trying to cover a very wide angle with a low resolution isn’t feasible, as an item of interest simply doesn’t contain enough pixels to provide usable recognition (quite common on fisheye cameras unfortunately). The safest bet is to pick a high-resolution camera to cover only the area you need. This will provide the largest and most detailed image on screen of what you’re interested in viewing.
Previously, anything above 0.4MP was strictly the domain of IP cameras. As mentioned above however, advancements in technology have allowed the production of HD analogue cameras, capable of up to 5MP (and apparently soon 4K!). With 4K set to supersede 1080p and become the standard in TV and PC monitors, it looks set to become far more prevalent in the next few years for CCTV too.
Focal Length Differences
Without a shadow of a doubt, the absolute most frequently asked question we receive is regarding focal lengths, and what viewing angles different focal lengths will offer. For good reason, too – it’s a very important decision in the system spec process, and can greatly affect image quality. You wouldn’t want to use a wide-angled lens to view a number plate from 50m away because you’d have no hope of reading it, and so it’s imperative you pick the right focal length for the job at hand.
The focal length (measured in mm) refers to the distance from the camera lens and the image sensor whilst the image is in focus. This directly dictates the viewing angle a camera will deliver, and thus the degree of zoom the camera will have.
IP cameras with a fixed focal length come in four standard focal length options, and these approximate to the below viewing angles:
- 2.8mm = 90° horizontal field of view
- 4mm = 60° horizontal field of view
- 6mm = 45° horizontal field of view
- 12mm = 25° horizontal field of view
The common misconception is that a wider viewing angle will always be better – you can see more, right? The problem there is that objects of interest such as a face or a number plate will appear smaller in the scene and take up less pixels-per-inch, providing a less detailed and smaller image of what you’re actually interested in seeing. So, it’s best to just use only the viewing angle you need to cover what you want to monitor.
