Surveillance Resolutions Explained
You’re probably used to seeing “Full HD” or “4K”, or other similar terms mainly used for TVs. While these terms can relate to surveillance equipment, there’s a whole bunch of other resolutions thrown into the mix for surveillance which can ultimately confuse things even further.
When it comes to watching your favourite movies, more resolution is better - we probably all agree on that. The same applies to your surveillance equipment, but it’s about far more than the latest blockbuster. It could easily mean the difference between catching a criminal, or not. Consider a scenario where someone has broken in to your home or office. The intruder was captured on your surveillance system - great! But... there’s a logo on their shirt, can you make out what it says? There’s a tattoo on their arm, can you tell what it is? They’ve got something in their hand, was it a clue? This is where the quality and resolution of your surveillance equipment could mean the difference between an arrest, and no arrest, despite you having surveillance footage of the intrusion. It’s the detail that matters.
You must keep in mind when selecting equipment, that every component matters. You wouldn’t connect a Blu-ray player to a TV from the 70s and expect Full HD would you? If you have Full High Definition cameras installed, but you’re recording them on an old recorder that records at tiny resolutions, then you will never be able to see the find detail the high definition cameras are producing. Don’t leave it until the time you need the footage for the police to find out it’s not recording the way you think. Match the capabilities of your cameras to your recording equipment, so you’re maximising the overall investment in your equipment. If you already have an exisiting installation, but are expanding or replacing your recorder only, you can of course upgrade the recorder knowing the additional capability is there if you upgrade cameras at a later date. The same applies with higher grade cameras. Just remember you’ll need to upgrade your DVR before you can record at the increased quality too.
There is one exception to the resolution rule, and that is your monitor. Many surveillance installations don’t require active monitoring of the surveillance feeds, but if you do, your monitor doesn’t have to match the resolution of your cameras. Of course, if you’re watching someone in your store to check they’re not stashing something in their pocket, a high definition monitor (assuming the rest of the installation matches) is probably not a bad idea. But if you’re mainly concerned with a break-in overnight, and you merely use the monitor to check everything’s still operating as expected, then you can get away with just about any monitor that’s compatible with your recording equipment. Because the monitor is at the end of the chain, after the recorder, you can always connect a higher resolution monitor to the recorder if you’re playing things back after an event has occurred, and you’ll see it all in the resolution it was recorded.
To make things easy to compare, we’ve provided the approximate “megapixel” count (when it’s not used in the name already). One megapixel is equal to one million pixels. The megapixel count is achieved purely by multiplying the horizontal and vertical resolutions together. It’s a reasonably good way of comparing digital resolutions. To maintain simplicity, the megapixel number tends to be rounded to the nearest whole or half megapixel. It’s also important to note that the actual resolution may vary by a small percentage when comparing different manufacturers. Whether your 4MP equipment is 2560 x 1440 pixels, or 2688 x 1520 pixels, is going to make very little difference to the overall quality of the picture. These are usually a result of equipment design and manufacturing differences, and really aren’t worth worrying about too much when comparing specifications.
You’ll still find CIF quality equipment available, but no nearly as common as it once was, as higher resolution equipment continues to fall in price. It provides 352 x 240 (0.1 Megapixels) resolution. We no longer carry any CIF resolution equipment.
You’ll find D1 resolution offered on a number of our low-cost solutions. It provides 704 x 480 (0.3 Megapixels).
Providing reasonable resolution but still in a value price range. 928 x 480 (0.5 Megapixels). 960h is the same vertical resolution as D1, however it has a widescreen aspect ratio, providing more pixels overall.
720p was the first resolution classified as high definition, even for televisions. Now almost everything is full high definition, but high definition is still used in many surveillance cameras 1280 x 720 (1 Megapixel).
This is the most common TV standard, and is considered “Full High Definition”. 1920 x 1080 (2 Megapixels). One major benefit of 1080p hardware is it matches pixel-for-pixel, many off-the-shelf displays designed for computers or TV.
Providing a marginal increase in resolution over Full HD 1080p, with a resolution of 2560 x 1440 pixels. It provides a marginal increase in resolution over Full High Definition 1080p.
While less common in surveillance (more common in video production), 4K cameras have a whopping 3840 x 2160 pixels, which equals over 8 megapixels. Unless you have absolutely critical surveillance requirements (ie, guarding Fort Knox), the cost of 4K equipment and recording increases so much, it’s probably not yet worth your consideration. However with technology pacing as fast as it does, this will rapidly change and we’ll see 4K as the standard for surveillance, as is rapidly occurring for computer monitors and TV viewing already.
TV lines came about when most recording was done with analogue hardware, with tape-storage being the common method. The TV Lines / TVL standard is falling out of favour to Megapixel specifications, mostly because onece we hit 1000TVL, it all started getting a little difficult to track. For a basis of comparison however, a 600TVL resolution is approximately 0.4 megapixels, or 1000TVL is approximately equal to 0.9 megapixels. So you can see once we enter high definition territory (2 megapixels or more), the TVL standard becomes a little difficult to manage.
The quality of resolution you need is really determined by your own specific requirements. While “more is better” when it comes to resolution in many ways, consider your own budget and circumstances to find a balance between cost and quality. If you would still like to chat to someone very knowledgeable about surveillance and resolution, find one of our friendly team who can help you find what you need.
|The following image shows relative size differences based on resolution. It links to an actual-size version. If you display it on your computer at 100%, it will highlight the differences in size, relative to the pixels in your computer monitor.|