DDNS – Free Dynamic DNS Providers

We maintain the list of Dynamic DNS (DDNS) providers online. Dynamic DNS is a method that allows you to notify a Domain Name Server (DNS) to change in your active DNS configuration on a device such as a router or computer of its configured hostname and address. It is most useful when your computer or network obtains a new IP address lease and you would like to dynamically associate a hostname with that address, without having to manually enter the change every time. Since there are situations where an IP address can change, it helps to have a way of automatically updating hostnames that point to the new address every time. Enter DDNS to the rescue.
We are proud to be considered the top resource online for information on dynamic dns providers. This is a gentle, not-too-technical introduction on it, how it works, and a comprehensive list of mostly free providers. We have also provided some dynamic dns reviews on various hosting companies to help you better decide who to choose!

If you like this list, please link to it will help others find this free list more easily!

Name	URL and domain selection	Subdomains?	Domains?
dnsdynamic.org (June 2011)	http://www.dnsdynamic.org/ Domains: *.user32.com, *.tftpd.net, *.wow64, etc (12+) Free VPN Also Available	Free	Free
changeIP.com (June 2011)	http://www.changeip.com/ Domains: *.dumb1.com, *.wikababa.com, *.dynamic-dns.net, etc (100+)	Free	$3/mo $6/qr $15/yr
No IP (June 2011)	http://www.no-ip.com/ Domains: *.no-ip.com, *.servequake.com, *.sytes.net, etc. (21 domains)	Free (5 domain limit)	$15/yr
afraid.org (June 2011)	http://freedns.afraid.org/ Domains: *.afraid.org, many many others (they list about 300. no, really.)	Free (donations encouraged)	Free (donations encouraged)
dyndns.com (December 2011)	http://www.dyndns.com/ 18 Subdomains Available	No Longer Free	Free (Pro: $15/yr)
zonomi.com (June 2011)	http://www.zonomi.com/	Free	$10/yr
zoneedit.com (June 2011)	http://www.zoneedit.com/	Free	Free
cjb.net (June 2011)	http://www.cjb.net/ Domains: *.cjb.net	Free	N/A
Zerigo (June 2011)	http://www.zerigo.com/managed-dns	Free (Pro: $19/yr)	Free
3322.org (June 2011)	http://www.3322.org/ Chinese Domains: *.3322.org, *.8866.net, etc (quite a few, but seem to have trouble accessing their sites from US)	Free	N/A
oray.com (June 2011)	http://www.oray.com/ Chinese Domains: *.xicp.net, etc (in Chinese)	Free	N/A
DarSite (June 2011)	http://www.darsite.com/eng Domains: *.darweb.com	$100/year	$100/year
ddns.nu (5 Dec 2001)	http://www.ddns.nu/ Domains: *.cable.nu, *.optus.nu, *.evangelion.nu, several others	Reg Disabled	Reg Disabled
Deerfield (2 Nov 2002)	http://dns2go.deerfield.com/ Domains: *.dns2go.com, *.idleplay.net, *.dynamic-site.net, others	$9.95/year	$19.95/year
DHIS (June 2011)	http://www.dhis.org/ Domains: *.net.dhis.org	Free	N/A
DHS (9 Dec 2001)	http://www.dhs.org/ Domains: *.dhs.org	$5 (one-time charge?)	N/A
DNS 4 BIZ (2 Nov 2002)	http://www.dns4biz.de/ Domains: Unknown	Free (also for-pay options available)	$4.99/month
DNS Exit (2 Dec 2002)	http://www.dnsexit.com/	N/A	Free
DNS Made Easy (2 Nov 2002)	http://www.dnsmadeeasy.com/ Domains: *.dnsmadeeasy.com, others	Free	$4.95/year (up to 5 domains)
DNS Park (8 Dec 2005)	http://www.dnspark.com/services/dynamicDNS.php	N/A	$8.95/year
dnsd.be (5 Dec 2001)	http://www.dnsd.be/ Domains: *.dnsd.be	5 Euro per year for the first hostname; 4 Euro for additional hostnames mapped to the same IP.	N/A
DtDNS (9 Dec 2001)	http://www.dtdns.com/ Domains: *.darktech.org, *.dtdns.net, *.etowns.com, others	Free	$20/year
dyn.ee (9 Dec 2001)	http://www.dyn.ee/ Domains: *.dyn.ee, *.dynserv.[com/net/org]	Free	N/A
DynAccess (5 Dec 2001)	http://www.dynaccess.de Domains: *.dyn-access.(com/net/org/de/info/biz), several others	5 Euro/year (or more, depending on name selected)
DynamIP (5 Dec 2001)	http://www.dynamip.com/	N/A	$3/month
Dynamx (5 Dec 2001)	http://www.dyn.ro/ Domains: *.dynam.ac, *.dyn.ro, *.my-ho.st, *.irc-chat.org	Free	N/A
dyndns.dk (9 Dec 2001)	http://dyndns.dk/ Domains: *.dyndns.dk, *.kyed.com, *.lir.dk, *.yaboo.dk	Free	$10/year
dyndsl.com (5 Dec 2001)	http://www.dyndsl.com/ Domains: *.dyndsl.com, *.45z.com, *.au2000.com	Free	N/A
dynip.com (9 Dec 2001)	http://www.dynip.com/ Domains: *.dynip.com, others	$35.95/year and up (based on domain name chosen)	$159.95/year
dyns.cx (5 Dec 2001)	http://dyns.cx/ Domains: *.dyns.cx, *.dyns.net, *metadns.cx, others	Free	15 Euro/year
DynUp (5 Dec 2001)	http://www.dynup.net/ Domains: *.dynup.net	Free	N/A (“coming soon”)
Easy DNS (5 Dec 2001)	https://web.easydns.com/	N/A	$19.95/year
Home PC (5 Dec 2001)	http://www.homepc.org/ Domains: *.homepc.org	Reg Disabled	N/A
Hotline DNS (5 Dec 2001)	http://www.hldns.com/ Domains: *.hldns.com	Free	N/A
Microtech Ltd. (5 Dec 2001)	http://www.microtech.co.gg/dns/ Domains: *.freelancedeveloper.com, *.ohflip.com, *.microtech.co.gg, *.easydns4u.com	Free	20 UKP/year
MiniDNS (5 Dec 2001)	http://www.minidns.net/ Domains: *.minidns.net	Free (“with quota”)	Free (“with quota”)
myserver.org (9 Dec 2001)	http://www.myserver.org/ Domains: *.myserver.org, *.USArmyReserve.com, *.WidescreenHD.tv, several others	Free	$24.95/year
Nettica (2 Nov 2002)	http://www.nettica.com/	N/A	$25/year, $45 for 2 years
Open Domain Server (5 Dec 2001)	http://www.ods.org/ Domains: *.ods.org	Free	$20/year for up to 5 domains
Planet DNS (9 Dec 2001)	http://www.planetdns.net/ Domains: *.planetdns.[net/org/biz/ca]	$19.95/year	$49.95/year
PowerDNS (5 Dec 2001)	http://www.powerdns.com/	N/A	Free for up to five domains, per email from site admin.
Prout (2 Nov 2002)	http://www.prout.be/dns/ Domains: *.prout.be, *.dyn.prout.be	Free	N/A
Sitelutions (2 Nov 2002)	http://www.sitelutions.com/info/sldns	N/A	Free
Static Cling (5 Dec 2001)	http://www.staticcling.org/ Domains: *.staticcling.org	Free	N/A
That IP (2 Nov 2002)	http://www.thatip.com/ Domains: *.thatip.com	$10 for up to 5 names	$10 for up to 5 names
Turnkey Hub (June 2011)	https://hub.turnkeylinux.org/ Domains *. TKLAPP.com Cloud Services with Turnkey Hub, but pricing based on Amazon EC3	Free	Free
TZO Internet (5 Dec 2001)	http://www.tzo.com/ Domains: *.tzo.com, *.tzo.net, *.tzo.org, *.tzo.cc	$24.95/year	$59.95/year $99.95/2 years
whyI (9 Dec 2001)	http://www.whyi.org/ Domains: *.yi.org,*.whyi.org,*.weedns.com,*.b0b.org	Free	N/A
Xname (June 2011)	http://www.xname.org/ Domains: *.xname.org	Free	N/A
Widge DNS (3 Dec 2002)	http://dns.widge.net/	N/A	Free
World Wide DNS (5 Dec 2001)	http://www.worldwidedns.net/	N/A	$39/year

Choosing Between Wireless and Wired Home Security System

There are many types of security devices that can be used as per an individual’s requirements. The primary classification for security systems is the wired and wireless category. Most devices in the security systems come with wired as well as wireless models. Both have their own advantages and disadvantages. Let us understand some basic differences that will help you to decide in favour of wireless or wired home security systems.

Differences between Wireless and Wired Home Security Systems

The most obvious and the biggest difference in both systems is that of wires. However, it is not as easy as it appears. The presence or absence of wires in a security difference makes changes in its installation, maintenance, hardware and software. Wired systems involve running a wire from the control panel individually to all the components of the security system.
Wired home security systems need an expertise in installation. A number of holes need to be drilled and a bunch of wires need adjustment without damaging the electric wires and the plumbing lines. It is best to make a pre-wiring plan when your house is still under construction. Other than additional wiring, make extra electric sockets at places that might need protection like doors, windows, staircases, etc. Install electric sockets outside your house as well.
In case, you are buying an already constructed house, it is best to take the help of a professional. You can call an electrician to do the wiring or take help from a handyman if your DIY skills can be applied. However, do not cause additional damage to your wirings in an over enthusiasm to install the system yourself. Also, opt for wired systems if you are engaging a dealer to do the job as they will in any case charge installation fees.
On the cost front, wired systems win hands down as the components are cheaper. However, installation is a very labour intensive process and needs sufficient expertise. The cost of installation is generally very high in these systems. Add to this the additional cost incurred if anything goes wrong during the wiring process. Wireless components are expensive but you can save by installing them yourself.
Wired systems are easy to maintain and easy to expand. Updating and upgrading is also easier in case of wired security systems. Wireless systems are generally restricted in terms of maintenance and become obsolete faster but they offer the latest in terms of technology. Wireless systems, though easy to install, are generally bigger in size and need to be constantly monitored for batteries.
However, is you want to have a less intrusive addition to neatly fit into your home decor, wireless devices are the best option for you. Owners of antique homes might also prefer wireless system to prevent any damage to the property. Wireless systems are also good for areas where wiring cannot be fitted easily like the lawn or external gates.
Both systems have their own advantages and disadvantages. Some people use a combination of wired and wireless devices to take the best out of both.

CS Vs C Mount Cameras

Modern cameras and lenses are generally CS mount rather than C mount. With CS mount cameras both types of lenses can be used but the C mount lens requires a 5mm ring (VM400) to be fitted between the camera and lens to achieve a focused image. With C mount cameras it is not possible to use CS mount lenses as it is not physically possible to mount the lens close enough to the CCD to achieve a focused image.

C Vs CS Mount Lens

 
The physical difference is the CS mount lens is designed to be mounted ~5mm closer to the image sensor than a C mount lens. (C-mount lenses are designed to be mounted 17.526mm in front of the image sensor vs. 12.5mm for CS-mount.) You can always use a C mount lens on a CS mount camera by using a 5mm spacer ring (many cameras now have C/CS selectable adjustment screws or rings). You can never use a CS mount lens on an older style C mount camera unless you are willing to physically modify the camera. Cost wise the CS mount lens is much less expensive since it uses fewer glass elements. Quality of image is the same. C mounts are becoming less and less popular and are generally only used on the more telephoto focal lengths such as 25, 50 and 75mm, and bigger zooms.

 
Both the C and CS mount are 1 inch wide (25.4mm) with 32 threads per inch (0.03125 inches or 0.79375mm). This dimension comes in handy if you need to insert a spacer to obtain proper focus. Unscrew the lens (or unscrew the camera from the mount in the case of telescope use and count the turns until proper focus is obtained. Multiply the above dimension by the number of turns to obtain the needed spacer or washer. (Washers are sometimes used as spacers if there are enough threads available.) Example: 1.25 turns x 0.79 mm = 0.9875 or ~1 mm. Many cameras (especially newer ones) have set screws to allow small adjustments in the distance between the lens and the image sensor.

Troubleshooting

A lot of the time when someone is using a CS mount security camera they will sometimes get a fuzzy picture and not be able to focus the image properly. If you look at what we have discussed so far you can probably figure out a possible solution to this. The most common mistake people make is that they will mount their CS mount lens onto their security camera while the 5mm ring is still attached. This ring is only useful if you are using a C mount lens. By simply removing this ring they will allow the CS lens to get close enough to the CCD chip to obtain a proper focus.
By taking the time to understand these differences in mounting for C and CS mount cameras and lenses you will help prevent damages to your surveillance equipment and reduce your workload.

Human Rights Act for CCTV

It is possible that CCTV usage could well be viewed as a possible infringement/invasion of your Human Rights under the Human Rights Act 1998.

So what do you do if your Neighbor is pointing their CCTV at you?

The Human Rights Act of 1998 could assist you and we would advise you to gain thorough advice from a solicitor who has expert specialist knowledge in this area.

The right contained in Article 8 is known as a qualified right which means that there may be circumstances in which some interference with it is justifiable. This right means that an individual has the right to the level of personal privacy which is compatible with a democratic society, taking into account the equivalent rights and freedoms of others. Any interference with this right by a public authority may be subject to a test of acceptability.

The state and public authorities are permitted to interfere with an individual’s Article 8 right to privacy if the interference has an obvious legal justification. Amongst other reasons, this could be because the interference is necessary to protect national security or for the prevention of crime. In addition to having a clear legal justification, the amount of interference with the right must be proportionate to the end result achieved and only go as far as is required to achieve that result.

Public authorities, including the police and local councils, must balance the benefits of using CCTV against an individual’s right to privacy.

The HRA is superior to all other legislation and should always take first preference. We advise you to seek specialized knowledge from a Solicitor who is an expert within Human Rights Issues and Legislation, it is an extremely complex area of legislation.

HD CCTV over coax

The technology commonly called HD CCTV implements SMPTE HD-SDI standards from television broadcast technology and can transmit video at 720p or 1080p resolution over RG59 cable to a distance of at least 100 meters. HD CCTV offers the benefit of providing high-resolution (megapixel) video, over conventional analogue coaxial cables.

PROVISION-ISR HD CCTV cameras offer a standard resolution of 1080P (1920 x 1080), equivalent to 2, 1 megapixels. 1080P provides over 24-times higher resolution compared with CIF and 6 time higher resolution than D1.

While Analogue cameras continue to improve, it is still subject to the limitations of the PAL/NTSC TV format, adopting a new HD standard which enables the camera to push video resolution beyond 700TVL and offering HD quality CCTV. HD CCTV is designed to be a drop-in replacement for existing analogue CCTV, requiring only a change of camera and DVR. Both new and existing installations can use CCTV industry standard coaxial cable (RG/59, RG/6 and RG/11).

HD CCTV advantages

* HD CCTV is a digital transmission of uncompressed HD video over coaxial cable.

* HD video: true 1080P or 720P HD video quality.

* Perfect clarity with no analogue noise.

* Uncompressed-nearly zero latency and no compression artifacts.

* Coax cable: immune to network failure.

* Easy upgrade: using same infrastructure as analogue system, just replace camera and DVR.

* Familiar user interface: for the installer/operator, no difference between CCTV and HD CCTV except for higher resolution.

* Unified standards.

Provision DVR and cameras

Provision’s HD-SDI DVR, SA8800, was designed to provide installers and customers with an easy entry point to the world of HD CCTV. It provides, in one chassis, both D1 ports (four channels) and full HD 1080 ports (four channels) allowing you to upgrade your traditional analogue CCTV system to full HD at your convenience. Cameras monitoring a sensitive spot can be replaced first while existing cameras will not require change or adjustment.

HD-SDI technology uses the same infrastructure as your existing analogue installation, allowing you to replace your existing cameras and DVR in very little time and with zero configurations.

Provision ISR HD DVRs are equipped with powerful CPU core technology to enable processing of four real-time channels at full HD (1080P) and four real-time channels at D1. Our DVR operates with H.264 main profile compression format and advanced industry SOC techniques to ensure real-time recording in each channel and outstanding stability of the system.

Provision’s ISR HD-SDI cameras implement the latest video processing technology and provide advanced features: Digital image balancing-delivering accurate picture in all light conditions, WDR capabilities, privacy masking, image effects and more due to true day and night functionality (ICR), DSS (Digital slow shutter), Advanced 3D-DNR (noise reduction) and Smart IR technology (all cameras provide an excellent night performance).

Benefits of HD cameras in different sectors

High-definition (HD) cameras are the best suited for today’s video surveillance needs. That said, we must remember that all HD cameras are megapixel (MP), but not all megapixel cameras are HD. The biggest difference between a megapixel camera and the high-definition cameras is that HD images use the 16:9 widescreen aspect ratio and megapixel produces images in a 4:3 aspect ratio.

HDTV provides a higher resolution and higher resolution translates into more detail, which in turn leads to better possibilities for identification. In addition, a true HDTV network camera provides full frame rate and extended colour fidelity, for an even better viewing experience.

To reiterate, all HD cameras are megapixel, but not all megapixel cameras are HD, and good quality, easy installation, and ease of use will set HD apart from standard analogue and MP systems.

Retail

In retail, theft and shrinkage can be drastically reduced through effective video surveillance. HDTV network cameras have an important role to play, for example by giving an overview – without any blind spots – of shops and stores.

City surveillance

HDTV network cameras are typically used in city surveillance situations to provide high-resolution video streams from locations where there is a need to be able to clearly identify people and objects, or get a larger overview.

High security premises

Casinos and airports, together with passport controls, banks and similar high security premises, are areas where the requirements on the surveillance cameras often include high image quality and detail as well as full frame rate, making HDTV network cameras the natural choice.

Transportation

Security and safety for both passengers and staff are highly prioritized issues for public transportation authorities around the world. HDTV cameras at stations, terminals and airports as well as on-board buses and trains, provide valid evidence in the event of criminal incidents.

CCTV Video Baluns

CCTV video baluns, also known as UTP baluns, allow traditional coax cable to be replaced by category 5 and other forms of twisted pair wire in CCTV video camera & surveillance installations. Video baluns allow installers to use more cost effective structured cabling techniques to wire security cameras. By using video baluns, UTP wire such as cat-5 can be run over longer distances easier than coax cable and for less money. Active balun transceivers enable UTP wires for cameras to be run distances up to 3,000 feet.

Video Balun Passive

The origin of the word balun is bal(ance) + un(balance). Video baluns, also known as CAT5 baluns.  A video balun is placed on both ends of the CAT5 cable run and uses one of the the twisted pairs from the CAT5 cable to transmit the video from the camera to a DVR or monitor.  There are also multi-camera baluns that can use the four twisted pairs in CAT5 to transmit the video for up to four cameras.   Most security camera installers are familiar with using RG59 coax cable for CCTV, as this is the industry standard cable and allows installers to run both the video from the camera and power to the camera using a single cable run.   There are versions of video baluns that also support running power to CCTV cameras in addition to the video.  These are some of the most common reasons that a security installer would choose to use CAT-5 cable instead of RG59 for a CCTV application.

• The location of the installation already has CAT5 cable pre-run and the installer wants to use it.
• The distance of the cable run exceeds 700 feet (the maximum distance supported by RG59 without a video amplifier).
• CAT5 cable typically costs less than RG59 cable.

The following types of video baluns are available and used in different circumstances.

Passive Video Balun with Power Connector

Passive Video Baluns

Passive video baluns are not powered and support cable distances up to 1200 feet.  These baluns use only one of the twisted pairs in the Cat5 cable.  The CAT5 is attached to the baluns on both end using screw terminals or other connection types. The balun has a BNC connector that gets connected to the camera on one end and a DVR or monitor on the other. 

Video Baluns with Power

Video baluns with power support running low voltage power to CCTV cameras in addition to transmitting the video signal.  For baluns that also supply power to cameras, one of the twisted pairs from the CAT5 cable is used for video and 2 pairs are used for power.

Passive Video Balun with Power Connector & Data - for PTZ Camer

Installers attach one pair for the positive and one pair for the negative power leads.  There are also video + power baluns that use RJ-45 connectors instead of the cable terminals, and even some models that support audio as well.  Some installers prefer this, especially when using pre-made network cables with the RJ-45 ends already attached.  An important note is that the distance that power is unable to be run is much lower than video and is still limited by the voltage and guage of cable being used. 12V DC typically begins to drop after 200 feet. The below video demonstrates how to use passive video baluns with power.

Active Video Baluns

Active video baluns include a power supply and act also as an amplifier so that cable distances can be increased beyond 1200 feet (the limit for passive baluns). 

Active Video Balun

Multi Ch Video Balun

An active balun receiver can be used on the DVR or monitor end of the cable with a passive balun on the camera end to boost the maximum effective distance to 2000 feet.  When an active transmitter balun and active receiver balun are used together, the effective distance of the cable increases to 4000 feet for color cameras and 5000 feet for black and white. The below diagram illustrates the wiring used when installing active video baluns. Please note that power is required for both the transmitting and receiving unit.

Wiring Diagram

Multi-Camera Baluns

Multi-camera video baluns allow each twisted pair of a CAT5 to be used for one camera, effectively allowing an installer to run video for up to four CCTV cameras over a single CAT5.  The below diagram illustrates how a multiple camera video balun is wired.

Multi Camera Baluns

Internal Circuit of Baluns:

Setting up a secure wireless network with the TP-Link TL-WR541G

Setting up a secure wireless network with the TP-Link TL-WR541G

OR

In the picture above the address bar has http://arindamcctvaccesscontrol.blogspot.com OR http://www.google.com in it. Just replace all of that with the internal IP address of your router. By default the IP address should be set to 192.168.62.1.

You should see a box prompting you for your username and password. Enter your username and password now.

The Default Router Username is: admin

The Default Router Password is: admin

Click the Ok button to log in to your router.

Click the Wireless link near the left side of the page.

You should now see a new menu. In this new menu, click Wireless Settings.

In the box called SSID put a name that you make up. You will need to remember this name because it will be used to connect to your wireless network. Do not make it obvious to guess, the network name should be difficult for your neighbors to guess. If you can not think of anything, simply use your first name.

In the box called Channel, pick a random channel number. Channels make it so that you and your neighbors can use your own wireless networks without interfering with each other. By picking a random channel you reduce the chance of your neighbor using the same channel as you.

Turn on the option called Wireless Router Radio.

Turn off the option called SSID Broadcast. This turns off the broadcast of your networks name making it more difficult for other people to find your network. You do not want to broadcast your networks name.

Turn on the option called Wireless Security.

Choosing your network security type can be challenging. Use the table below to help you decide which encryption type is best for you. 

Select WEP from the Security Type drop down box.

Select Open System from the Security Option drop down box.

Select Hexadecimal from the WEP Key Format drop down box.

Put a dot into the Key 1 radio button.

If you are using WPA

Now you need to make up a passphrase.

Your WPA key can be a plain text, human readable sentence. Make sure it is long, however, because recent hack attempts have exploited short WPA passphrases. Your WPA passphrase should be at least 30 letters long.

Onnce you have made up your passphrase, write it down somewhere. You will need it at each computer that you are going to connect to your network.

If you are using WEP

Now you need to make up your network key.

It doesn't matter what this key is, as long as it is random. A network key is a password that is 26 characters long, and made up of only the letters A,B,C,D,E,F and the numbers 0,1,2,3,4,5,6,7,8,9. If you are using 128 bit WEP, then your key must be exactly 26 characters long, and the more random it is, the better it is. Here is an example of a random 128 bit network key:

7F5B3FD23A8EC290AC682DF8FA

Onnce you have made up your key, write it down somewhere. You will need it at each computer that you are going to connect to your network.

Now put the key you made up in the box called Key 1.

Select 128bit from the Key Type drop down box.

When you're finished, click save near the bottom of the screen to save your changes.

And that's it! You're done!

Choosing a Frame Rate on CCTV

Movies on film are almost exclusively projected at 24 FPS. Television, however, does not have an internationally accepted frame rate. In Europe and many other countries, PAL and SECAM use 25 FPS, whereas NTSC video in North America and Japan uses 29.97 FPS. Other common frame rates are usually multiples of these.

Note: Converting video formats from one frame rate to another is technically challenging, and there are often unwanted visual side effects. This is especially true when the frame rates do not evenly divide. For example, converting 30 FPS to 60 FPS is fairly easy to do, but converting 29.97 FPS to 25 FPS is much more difficult. Making sure audio stays in sync throughout the conversion is yet another challenge.

Some digital video formats support several frame rates within a single format, allowing variable frame rate video recording and film (24 FPS) compatibility.

Frame rate	Media	Description
24 fps	Film; high definition video	This is the universally accepted film frame rate. Movie theaters worldwide almost always use this frame rate. Many high definition formats can record and play back video at this rate, though 23.98 is usually chosen instead (see below).
23.98 (23.976) fps	Film; high definition video with NTSC compatibility; NTSC	This is 24 fps slowed down by 99.9% (1000/1001) to easily transfer film to NTSC video. Many high definition video formats (and some SD formats) can record at this speed, and it is usually preferred over true 24 fps because of NTSC compatibility.
25FPS	PAL; high definition video	The European video standard. Film is sometimes shot at 25 FPS when destined for editing or distribution on PAL video.
29.97 fps	NTSC; high definition video	This has been the color NTSC video standard since 1953. This number is sometimes inaccurately referred to as 30 fps.
30 fps	High definition video; early black-and-white NTSC video	Some high definition cameras can record at 30 fps, as opposed to 29.97 fps. Before color was added to NTSC video signals, the frame rate was truly 30 fps. However, this format is almost never used today.
50 fps	PAL; high definition video	This refers to the interlaced field rate (double the frame rate) of PAL. Some 1080i high definition cameras can record at this frame rate.
59.94 fps	High definition video with NTSC compatibility	High definition cameras can record at this frame rate, which is compatible with NTSC video. It is also the interlaced field rate of NTSC video. This number is sometimes referred to as 60 fps, but it is best to use 59.94 FPS unless you really mean 60 FPS.
60 fps	High definition video	High definition equipment can often play and record at this frame rate, but 59.94 FPS is much more common because of NTSC compatibility.

Important: Many people round 29.97 FPS to 30 FPS, but this can lead to confusion during post-production. Today, it is still very rare to use a frame rate of 30 FPS, but very common to use 29.97 FPS. When in doubt, ask people to clarify whether they really mean 30 FPS, or if they are simply rounding 29.97 FPS for convenience.