Video Management Software: An Introduction

Video management software (VMS) is a fundamental component of an IP camera system.

VMS lets you view, store, and manage your surveillance video feeds. A good VMS solution might let you switch between live feeds, zoom in on important features, search for a video from two weeks ago, or trigger an alarm when a vandal is picked up by a camera.

It might provide many features that improve security, including secure remote access, failover redundancy, and video encryption.

When shopping for a video management solution, there are many things to keep in mind. In this article, we’re going to cover the primary questions you should be asking.

 

Milestone Systems

 

Video Management Software: Things to Look For

What should you be looking for in video management software? Here’s a 1000-ft view.

Do I have to pay for video management software?

Many IP camera manufacturers offer free VMS solutions. These solutions can suffice for small deployments, but are limited in scope and feature-set.

Milestone Systems, one of the premier video management companies, offers Milestone XProtect®, an elite VMS solution that scales based on your needs. You can get XProtect® Essential+ for free, which supports up to 8 cameras at a single site.

There are also open source VMS solutions available, including iSpy, Shinobi, and Zoneminder. We suggest these solutions, which are worthwhile, only to the kind of person who enjoys customizing their Linux distro or programing a Raspberry Pi for fun on the weekend. If you know what we mean.

What devices are supported?

The best VMS in the world is useless if it doesn’t support your camera.

On their websites, most companies will have a product compatibility finder or guide. For example, here’s Milestone’s hardware compatibility tool. Always check these tools before pressing “Buy.”  https://www.milestonesys.com/community/business-partner-tools/supported-devices/

There has been an increasing open standards movement in IP cameras in recent years, which has greatly improved the situation.

IP camera makers have come together to agree on open standards under the banner of ONVIF, the Open Network Video Interface Forum. ONVIF Profiles indicate the interoperability of cameras, recorders, and more. See our previous blog on ONVIF for more information.

How many cameras does it support?

The most pressing limitation of free VMS solutions is that they don’t support many cameras. If you have only a small shop to surveil, needing only three or four cameras, then a free VMS option might be best.

Milestone XProtect® supports unlimited recording of 8 connected cameras. If you have a larger space that requires more cameras, you’re going to need more support.

How scalable is the solution?

“Scalable” is a tech industry buzzword meaning how simple it is to add or removes devices or users from a system.

Scalability is one of the key advantages of IP cameras over traditional CCTV cameras. CCTV, as the name states, require “closed circuits,” that is, a whole different wiring system. IP cameras, however, connect using Ethernet cables, making them vastly more scalable.

When thinking about the scalability of VMS solutions, consider whether you hope to expand your camera fleet in the future. If yes, make sure that you don’t lock yourself into a system that will prevent expansion. Give yourself room.

Does it offer mobile integration?

Many VMS solutions now offer you the opportunity to view live feeds and stored video remotely from mobile devices.

Convenience is the benefit, and security is the primary thing you should look for. How does the system secure the connection between your mobile device, the WiFi or cellular network you’re using, and the IP network that the camera is running on.

The convenience factor can be immense, but it shouldn’t outweigh security.

What are your video streaming options?

VMS should give you a simple method of streaming video. Does the VMS interface let you view and switch between feeds easily?

Another major question is: How many feeds can you view at once? Milestone XProtect® Essential+, for example, only lets you view one live stream. (You can have another simultaneous stream for recording.)

But if you want more live feeds than that, you’ll have to find a VMS (and a computer with processing power) to support the number of feeds you want.

You might need to look into the video codecs that are supported, particularly if you hope to use cutting-edge ones like HEVC (H.265), which is highly efficient but still sparsely supported.

What are your video storage options?

You need to store video somewhere, right? Usually this is done on a network-attached storage solution like a network video recorder or a server. Does your VMS work with these?

ONVIF has developed open standards for network video recorders, which is increasing the number of options you have for video storage.

And a final storage feature to look for is redundancy. In computer terms, redundancy means having a back-up in case of hardware failure. If a hard drive goes, which is always a possibility, you don’t want all your video evidence to disappear.

What features are supported?

The list of features that VMS solutions now support is quite incredible.

A particularly important one for many people is PTZ, pan-tilt-zoom. Some VMS solutions let you directly control the camera from a computer or even mobile phone. For busy areas like stations or lobbies, you might want to have a security guard watching live feeds. If they see something, VMS that integrates PTZ functionality will let them do their job better.

Another feature many people like is motion detection. Take a carpark. Motion detection would save you a huge amount of space in storage, because most of the time a carpark is completely still: it’s just cars sitting there. You only need to track people and cars entering and exiting.

How strong is the security?

IP cameras are supposed to increase your security, but if your VMS is unsecure, that can be really bad. IP cameras are network-based, which means hacking is a potential issue. Find a VMS with top-class encryption, and make sure you do your part by choosing strong passwords (or using a password manager).

 

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What Do Those Durability Ratings Mean for IP Cameras?

“IP67 Rated.” “IK10 Rated.” “NEMA Type 4X Rated.”

Looking over any spec sheet for a security camera (or smartphone!), you’re sure to come across a rating or code that sounds like one of those. But what do they mean?

The ratings refer to industry standards for durability. Each standard includes a method for testing an item to ensure it meets the standard. So you know if you see IP67, the item in question has been tested according to a reliable, universal method.

  • IP Rating — Resistance to ingress of solid particles and water
  • IK Rating — Resistance to impact
  • NEMA Rating — Quality of enclosure

IP and IK ratings are codified by the International Electrotechnical Commission. NEMA ratings are codified by the National Electrical Manufacturing Association.

The actual standards are quite technical. We’re going to translate those technical standards into language you can understand.

IP Rating — Resistance to ingress of dust and water

IP stands for International Protection. An IP code typically has IP and two numbers, e.g. IP67. Put together, the two numbers tell you how resistant the item is to ingress of solid particles or water. Sometimes there will also be a letter, which indicates an additional level of protection or something about the item.

Ingress is a fancy word that means “entering.” So an IP rating means how well protected the item is against dust or water getting in.

The two numbers in an IP rating each stand for something:

  1. Resistance to solid particles getting in
  2. Resistance to water getting in

First Digit

Number Meaning
0 No protection
1 Protects against large parts of the body
2 Protects against fingers
3 Protects against tools or large wires
4 Protects against thin wires, screws, ants, etc.
5 Dust won’t mess with item’s operation
6 Completely dust-tight

Second Digit

Number Meaning
0 No protection
1 Protects against dripping water
2 Protects against dripping water when tilted
3 Protects against spraying water
4 Protects against splashing water
5 Protects against water jets
6 Protects against powerful water jets
7 Protects against being submerged up to 1m under water
8 Protects against being submerged more than 1m (usually up to 3m)
9 Protects against powerful high temperature water jets

Additional Letters

Letter Meaning
F Resistant to oil
H High-voltage item
K Water jets used increased pressure
M Item was moving during water tests
S Item was still during water tests
W Weather conditions

If you’re looking at older equipment, you might see an IP code with a third number, e.g. IP66(9). That third number refers to resistance to impact and was added to IP codes in a non-standard way until the late 90s. To standardize this useful information, they came up with a new rating: IK.

IK Rating — Resistance to impact

IK ratings indicate how well an item resists impact, for example, from being hit or from being dropped.

Unlike IP ratings, the numbers of IK ratings all refer to resistance of impact, not to two separate things. The ratings are written IK01, IK02, IK03, etc., but the initial zero doesn’t indicate anything, nor does IK10 indicate two separate things.

IK ratings are based on joules, which is a measure of impact energy. To give you some idea, 1 joule is roughly equivalent to the impact of a medium-sized tomato dropped from three feet.

Number Resistance to Impact in Joules
00 No protection
01 0.14
02 0.2
03 0.35
04 0.5
05 0.7
06 1
07 2
08 5
09 10
10 20

NEMA Ratings — For enclosures

NEMA stands for National Electrical Manufacturing Association. NEMA ratings indicate the quality of the enclosure. They’re comparable to IP ratings, but not quite identical.

NEMA ratings are like IK ratings in that the numbers all not to be read separately. You’ll often see a letter as part of a code, e.g. NEMA Type 4X. As with IP ratings, the letters indicate additional protection (or in one case, a protection that’s omitted).

Type Meaning
1 General purpose
2 Drip-tight
3 3 — Weather-resistant
3R — Weather-resistant, except against windblown dust
3S — Weather-resistant, works when covered in ice
3X — Weather-resistant, plus corrosion protection
4 4 — Water-tight
4X — Water-tight, plus corrosion protection
5 Dust-tight
6 6 — Submersible
6P — Submersible for occasional extended periods
7 For hazardous conditions — indoor, against gases
8 For hazardous conditions — indoor and outdoor, against gases
9 For hazardous conditions — indoor and outdoor, against dust
10 Meets mining industry standards
11 General purpose — meets drip and corrosion tests
12 & 12K General purpose — meets drip, dust, and rust tests
13 General purpose — meets oil and rust tests

 
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ONVIF: Open Standards for IP Cameras

In our last blog, we mentioned ONVIF in reference to cross-brand interoperability. Today, we’re going to explain why ONVIF is important to your IP security camera system.

ONVIF stands for Open Network Video Interface Forum. It was started in 2008 by Axis, Bosch, and Sony to promote open standards for IP physical security technology, including IP cameras and IP access control devices. Today, a huge number of companies are ONVIF members.

What does that mean for you?

ONVIF means the customer has choice

If each manufacturer made cameras that only work with their own products, the customer would have very limited choice. Once they bought an Axis camera, they’d be stuck in the Axis ecosystem.

This might sound like something that manufacturers would love: locked in customers. But it limits innovation and, frankly, is an unpopular choice (for every company not named Apple). When you’re talking about something as important as surveillance or access control, it can actually be unsafe to lock customers into one platform.

Having a shared standard also means that current products can work with future products. Since IP cameras have a longer life-cycle, ONVIF means your investment is future-proofed.

Enter ONVIF.

If you purchase IP security devices that comply with the same ONVIF profiles, they will be interoperable. If you have a camera from one brand that supports ONVIF S and a recorder from another brand that supports ONVIF S, they will work together.

It makes it much, much easier for the customer.

(There might be the occasional exception for optional features.)

What are the ONVIF Profiles?

The ONVIF members agree on specifications for functions and codify them in profiles. The products are tested to ensure they comply with the profile. For example, one part of ONVIF Profile S is that the product must support the G.711, G.726, and AAC audio codecs.

There are currently five ratified profiles and one profile in the works.

ONVIF Profile S – Video streaming

ONVIF Profile S is the oldest profile. It was ratified in 2011. There are now over 8,000 products on the market that meet ONVIF Profile S.

It covers video streaming and a few other functions, like PTZ (pan-tilt-zoom) control, audio streaming, relay outputs, and IP address filtering.

Profile S lets a video management client know that when it wants to configure, control, or request information from an IP camera, like a stream of video, that it will be able to do that.

ONVIF Profiles C and A – Access control

ONVIF Profiles C and A deal with IP access control. IP access control refers to network-integrated door or gate entry systems, like an RFID card reader in a business office.

Profile C covers door control and event management. Profile A covers access management.

One additional nice feature of the ONVIF profile system is that if your IP cameras and your IP access control devices are on the same network and are ONVIF compliant, then they will be interoperable.

ONVIF Profile G – Edge storage and retrieval

ONVIF Profile G covers video storage, as compared with Profile S, which covers video streaming.

If you have a camera from one brand and a recorder from another brand, and they’re both ONVIF G compliant, then you know you’ll be able to record video. There won’t be any proprietary shenanigans that will limit your ability to gather video evidence.

ONVIF Profile Q – Quick installation

ONVIF Profile Q makes installation easier. It provides a method for quick discovery and basic configuration.

If you’re using a ONVIF Q camera and an ONVIF Q video management application, the application will be able to discover, configure, and control the camera right away.

Another important aspect of ONVIF Q is TLS (transport layer security) support. TLS means the data shared among devices on your network are secured, which is very important for sensitive material like surveillance video.

ONVIF Profile T (not yet approved) – Advanced video streaming

ONVIF Profile T is not an official profile, yet.

Like ONVIF S, it deals with video streaming, but it’s not intended to replace ONVIF S. Rather, it offers its own feature-set.

For example, it covers H.265 (HEVC) video streaming, which is a relatively new, highly efficient method of encoding and transporting video data. Another feature is HTTPS streaming, which improves security for browser-based video streaming control.

As things stand right now, ONVIF Profile T should be ratified in 2018.

 

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IP Camera Video Storage

How to store surveillance video is a primary consideration when setting up an IP camera system.

IP cameras are different from traditional CCTV cameras, because they’re connected to your computer network. CCTV cameras have their own system of wiring. That’s where the CC comes from: “closed circuit.” So they need a recorder that’s attached to that dedicated system of wiring.

There are two primary modes of recording surveillance video from IP cameras:

  1. Network-attached storage
  2. Local storage

Network-attached storage

We’re using network-attached storage to refer to any storage solution in which the video feed passes through a computer network to a storage device. You’ll often see network-attached storage or NAS used to describe a specific data storage product, a kind of consumer-grade external hard drive.

We’re using the term more broadly, although in the end they’re both just hard drives connected to computer networks.

Why use network-attached storage?

Network-attached storage offers many advantages. Here are a few.

  • Incredible space. Storage solutions for IP cameras can record vastly more video than traditional systems. Just think of the difference between a hard drive from 20 years ago and a hard drive from today. Yeah.
  • Scalability. Connecting additional devices to your network, and thus to your network-attached storage, is simple.
  • Physical security. Because the storage device is separate from the camera, you can
  • You can attach multiple storage devices, storage area networks, or RAID setups to protect your video evidence.
  • View from anywhere. Many network-attached storage solutions include options for viewing video feeds from any device that can securely access your network, including smartphone.

The most commonly used solutions for IP cameras are network video recorders or NVRs.

Network video recorders (NVRs)

NVRs are dedicated solutions for recording video through your computer network. You are probably familiar with a DVR (digital video recorder), which can store video from your TV. Think of an NVR as the same thing, except that it stores video from devices on your computer network rather than just the TV.

Because NVRs are designed for security camera deployments, they have features specific to the problem.

When shopping for an NVR, you’ll want to look for these features:

  • Camera feeds. Can you connect all the cameras to it?
  • Security. What data security measures does it offer?
  • Video management software (VMS). What software comes with or is needed to operate the NVR?
  • Live feeds. How many live feeds can be viewed at once? Does it have the correct interface (e.g. HDMI) for the monitor or do you need an adapter?
  • Expandability. Can you add or replace hard drives if you need to?
  • Video encoding. Does it support the video encoding file formats that your IP camera uses?

One final consideration is standards, that is, if the camera and storage device are interoperable. Cross-brand deployments might not work with each other, although the situation is getting better.

ONVIF is an industry forum that provides open standards profiles that indicate interoperability across brands. In a future article, we will discuss ONVIF in more detail.

Local storage

Many IP cameras give you options for storing video locally. This means that the video is recorded in the camera, not through the network.

Most of the time, this will be a slot for inserting an SD or microSD card. These little cards can hold a lot of data, with some options now getting up to half a Terabyte on a card barely bigger than a fingernail.

Local storage has one big limitation: access. If your cameras are in hard-to-reach places, local storage is not really an option.

Why use local storage?

There are several reasons why people choose local storage.

  • Redundancy. Local storage is often used in addition to network-attached storage to add another layer of redundancy; the two options work well together.
  • Price. SD cards are less expensive than network-attached storage.
  • Limited bandwidth. If your network is already strained, you can take the load off by keeping the video feeds off the network.
  • Price. For some, the idea of setting up network-attached storage is intimidating. SD cards are more limited but simpler.

How much storage do I need?

This is a tough question, because of all the variables you need to take into account. Depending on the deployment, you might need anywhere from around 300 Mb to 3 Gb per 24 hours per camera.

Rather than give you specific numbers that could be highly misleading, we’re going to list the variables you should take into account:

  • How many camera feeds?
  • What video resolution?
  • What frame rate?
  • How much motion is typical in the scene?
  • How long do you intend to keep the video?

As each of these variables increases, you need to increase the amount of storage space to plan for.

Another variable is the video codec or file format that is used for storing the video. Newer codecs like H.265 (also known as HEVC) can be much more space efficient than previous ones, but they might also provide compatibility issues.

In a future article, we will discuss how you can make your video feed more efficient to reduce your storage load.

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Shop Smart for IP Cameras: Resolution vs Sensor Size

When shopping for a security camera, most people look for resolution: either the Megapixel count (5 MP, 12 MP) or the catchy marketing term (4k Ultra HD, 1080p). People tend to think that bigger is always better. A 4k camera must be better than a 1080p camera, right? This is not necessarily the case.

Knowing how resolution affects your video security helps you shop smart. The size of the sensor can be as important as the resolution.

In this blog, we’re going to explain the relationship between resolution and sensor size. But first a little background.

How do digital cameras capture images?

The sensor of a digital camera is the equivalent of film in a film camera.

Light is let onto a sensor through a lens. The sensor receives and encodes the information, producing an image. Video is just a whole bunch of images presented sequentially so fast that our brains interpret it as the equivalent of movement in the real world.

We’re not going to get too deep into the technical details, but you need to know a bit.

Pixels and photosites

Image resolution is measured in pixels. Pixel stands for “picture element,” and means the smallest unit of a picture, that is, a single square of color. How does a camera determine what color a pixel should be?

A camera sensor is a sheet of prepared silicon of millions of photosites. A photosite is a light-sensitive cavity in this sheet of silicon. Each photosite produces a single pixel’s worth of information.

When light hits a photosite, electrons are energized. More light means more energy. A camera measures the changes in energy levels (voltage). The sensor sends this information along, and this information is what is used to produce an image.

In digital photography, an increase in light intensity increases the luminosity of a color, that is, how far on a scale between white and black a color is. An overexposed photosite produces pure white; an underexposed photosite produces pure black.

So that’s how we get shades. But who do we get color?

To produce a color image, manufacturers place a filter over the photosites. The filter blocks out certain wavelengths, allowing the camera to interpret what color light is hitting the sensor.

What does this have to do with resolution?

Resolution is the measure of how many pixels are in an image.

If an image measures 6,000 x 4,000 pixels, that comes to 24,000,000 pixels in total. The prefix Mega- just means million. So a 6,000 x 4,000 pixel image is a 24 Megapixel or 24 MP image.

You increase the number of pixels by increasing the number of photosites on a sensor.

Here’s where you can see how sensor size can be extremely important in determining the quality of an image.

To increase the number of pixels a sensor can produce, you need to either shrink or more tightly pack the photosites on a sensor. This can lead to less information gathered per photosite or energy bleeding from one photosite to its neighbors, causing inaccuracies.

Take that 24 MP image. If one sensor measures 0.5” wide and another sensor measures 0.75” wide, yet they both produce a 24 MP image, the first sensor needs to pack in photosites much more tightly than the second sensor.

In general, a more spacious arrangement of photosites leads to greater accuracy, improved low-light performance, and less noise. So a lower resolution on a larger sensor could improve your video picture quality.

And in the end, your surveillance video is all about accuracy.

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Top 5 Tips When Shopping for IP Cameras

All you want to do is protect your property with a security camera. You’re looking through the options. It’s overwhelming. Where do you start?

What IP camera is right for you?

Here are our Top 5 Tips to think about when shopping for an IP security camera.

  1. Conditions
  2. Area of Coverage
  3. Light Levels
  4. How Obvious
  5. Adjustability

 

1. Conditions

Are you installing the camera inside or outside? Do you need to protect against vandals?

The first thing to consider is Where Is This Going?

Outdoor cameras often have extra sealing or heating units to help them deal with the elements. Indoor cameras don’t need to worry about stuff like that.

The Operating Temperature Range tells you if it can deal with the cold or heat. The IP Rating or NEMA Rating tells you how well it deals with dust and water. The IK Rating tells you how well it deals with impacts.

If you’re worried about vandals, look for vandal-resistant cameras, which have extra protection like Torx security screws to prevent tampering.
 

2. Area of Coverage

How much area does the camera need to cover?

A camera in the corridor of an office building and one overlooking a carpark have very different needs.

The field of view tells you how broad or narrow a scene the camera lens captures. Note that if you have a zoom lens, the field of view will get smaller as the camera zooms in.

If you want a really broad field of view, look for a panoramic camera. Panoramic cameras stitch together multiple feeds into a single, very broad video. For open spaces, you can even install a 360° camera, which is exactly what it says on the tin.

For confined spaces, a narrower field of view is ideal. If you want to monitor a hallway, consider a camera that gives you a vertically oriented picture, like you see on a smartphone. This way you’re not wasting a lot of bandwidth monitoring walls. Axis makes IP cameras that support Corridor Format just for this purpose.
 

3. Light Levels

Do you need low-light or nighttime surveillance? Is there a lot of contrast?

High contrast scenes can be a big problem for cameras. By high contrast, we mean that there’s a big difference between dark shadows and bright light, like at the entrance of a building with an awning. Under the awning it’s dark, but on the sidewalk it’s bright. The human eye can adapt to these light changes easily, but cameras have a much harder time.

Another common problem is car lights at night. Everything is dark except for those bright pinpoints, which can ruin the surveillance video.

If you think high contrast will be an issue, look for an IP camera with a wide dynamic range.

Darkness can be a big problem for cameras, as you know from trying to take pictures at night with your smartphone. Like any camera, some IP cameras are better in low-light than others.

Most manufacturers tell you how well their cameras do in low lighting conditions. Check the lux rating. To give you some idea of what a lux rating means, 1 lux is roughly equal to the light of a single candle. The light of a full moon on a clear night is roughly 0.1 lux.

If you need low-light surveillance, look for an IP camera with a good lux rating.

For nighttime or pitch-black surveillance, look for infrared cameras or thermal cameras. Infrared cameras project infrared (IR) light, which the human eye can’t see. A camera sensor can pick it up, though, so it “sees” the reflected IR light. Many infrared cameras have integrated infrared illuminators.

Thermal cameras pick up heat signatures. You won’t get much detail, but you will have video evidence in any circumstance, since heat signatures are “visible” even in the thickest fog.
 

4. How Obvious

Do you want people to see the camera?

Sometimes you want people to know they’re being watched. It can help deter bad actors from even starting to mess with your property.

Other times you want the camera to be out of sight, out of mind. It can let people act more naturally if they don’t know they’re being watched.

When you’re shopping for an IP camera that you want to be seen, you might consider a bullet camera. Bullet cameras are your classic security camera shaped like bullets. They’re highly visible.

When you’re shopping for a discreet camera, you might consider a mini-dome camera or covert camera. These are made to be very small, so they’re hard for people to notice. You’d be surprised how small they get!
 

5. Adjustability

Do you need to pan, tilt, or zoom?

For many installations, a fixed camera is perfect. But sometimes you need the camera to move.

Moving from side to side is called panning. Moving up and down is called tilting. Moving in and out to get a closer or more distant picture is called zooming. Put the three together and you get PTZ.

PTZ cameras are adjustable from a distance. That means you can pan, tilt, or zoom from a computer or even smartphone, rather than needing to manually adjust the camera.

PTZ cameras are particularly useful when someone is actively watching the video feeds. They’re not as useful when you’re just passively recording.

Manufacturers are taking advantage of the power of IP cameras vs traditional CCTV cameras. They’re building in intelligence. You can now find PTZ cameras that automatically track or automatically zoom in on moving objects.
 
 
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Aperture and Importance to IP Surveillance Cameras

The aperture on an IP surveillance camera is the opening of the lens diaphragm that allows for light to pass through to the image sensor.  In IP surveillance, the image sensor is like a camera’s film, a larger image sensor is like having a larger piece of film and therefore more image detail. This is why Megapixel ratings are often misleading or not as important as you’d think, but we’ll go there in another post. Another way to think of the aperture is to think of it like the pupil of your eye, the larger your pupil, the more light that passes through. In darker light, your pupil gets larger to let more light pass, and in brighter light, your pupil gets smaller, so the light is not too intense.

In the IP surveillance camera world, the amount of light that passes is rated in “f-numbers,” and camera lenses typically have presets or “stops” called “f-stops” that allow users to dial-in or select a lens that is fixed on a scale like f/1.4, f/2.0, f/2.8, etc. When it comes to these “f-stop” numbers, the lower the number, the greater the opening/exposure. Alternatively, a higher number represents a smaller opening and less exposure. This is why you will see zoom lenses that have ratings from f/1.4 to f/4.0 because they allow less light as they zoom in on an object ultimately changing exposure and the image depth. It is important to note that the aperture needs to be appropriately dialed in with the shutter as they work together to set the overall exposure, but we’ll also cover that in another post.

Sample Lens Aperture

Sample Lens Aperture

Aperture affects exposure and detail

In addition to the amount of light on the object in the foreground, the aperture also controls the image background sharpness also commonly known as “depth of field.” For example, a lower f/stop means a larger or wider opening of the lens. This results in the ability to pick up foreground images in low light but with a blurrier background, whereas a smaller aperture would require greater light but allow for greater depth and a sharper background. Please note that it is essential to consider the amount of light to prevent washouts and overexposure although many cameras now have software to prevent such situations.

So, should I just buy the IP surveillance camera with the highest f-number?

No. When purchasing an IP surveillance camera, it is essential to consider the aperture to ensure you are getting the correct amount of light (not too much or too little) based on the camera placement along with other factors. Remember we want to rely on software light exposure correction as little as possible and want the lens hardware to do a lot of the heavy lifting. Having too much light can cause the image to wash out and having too little will result in an image that isn’t useful.

As a basic rule, here are some typical f-stops and their uses:

  • f/1.4 – excellent for low light situations; however, has a shallow depth of field.
  • f/2.0 – suitable for low light conditions, provides a bit more depth of field.
  • f./2.8 – requires more light but adds image definition of facial features, etc. For many zoom lenses, this will be the widest setting.
  • > f/2.8 in surveillance these are typically used by zoom lenses.