HD SDI Cameras vs IP Cameras
If it is only about the best image quality, CCTV security systems have come a long way in offering plenty of megapixels. There are two methods that ensure high quality videos and they are using IP Cameras and HD-SDICameras.
You get the option of choosing either 720p or 1080p videos but there is more to security cameras than just resolution. Here is a brief layout of both systems and the advantages/disadvantages of both.
High Definition – Serial Digital Interface or HD-SDI systems basically transfer HD quality video over standard analog cables. Many cable service providers currently utilize this technology for broadcasting HD television in congruence with FCC standards.
Folks who are looking to upgrade with the existing wiring system or lack the proficiency in dealing with networks will find HD-SDI systems helpful. It usually involves swapping of the cameras and DVR for HD-SDI cameras. All that remains after this is to ensure the same IP scheme for the DVR as the existing network and then enabling remote viewing through the port forward and router settings. As for new installations, you really don’t have to worry about anything since all wiring and setup is done in accordance with the highest standards of HD-SDI systems.
When you use HD SDI systems you really don’t have to worry about the bandwidth of the network as all the cameras are self-contained in themselves and directly link up with the DVR unless you are using remote viewing. In fact, the cameras themselves aren’t network devices so it requires less configuration too.
However with HD-SDI systems a major limitation is the cabling and distance of each cable type. It is usually agreed that the best cables to use for such systems is the RG-6 for better transmission rates. You can use RG6 cables for up to 300 feet without loss in transmission strength but with RG59 cables the transfer distance is usually limited to 200 feet at most. Another worry is the power in relation to transmission distance as longer the distance greater is the voltage drop. You may need boosters at regular points if you plan on wiring a lot of distance.
There are hybrid HD-SDI recorders that help in retrofitting using existing cables but they usually lack the required high quality and require specialized setups.
IP Camera Systems
IP Cameras can be simple or complex. The simplest type of IP cameras are PoE NVR or the Power over Ethernet Network Video Recorders that allow a total of 4 cameras to run directly using the NVR’s PoE switch. This system is best for plug and play cams where a simple network is created for cameras alone eliminating interference from any outside networks and the necessity to issue individual UP addresses. This is purely a basic installation and hence much easier to achieve than using HD-SDI cameras.
However, if you plan on using more than 4 cameras you will need NVRs with 16 channel units or more. Add to this the necessity of using a suitable channel PoE switch. An important consideration to keep in mind is that you will need two 4 Port PoE switches or a single 8 Port PoE switch for operating at most 8 cameras together.
To maintain constant communication modes, it is always best to add IP cameras to existing networks by first upgrading routers and switches to Gigabit. This provides the necessary speed to your existing network so that communication failures don’t occur. Another handy practice is to use a separate Gigabit switch for jumpers and then one cable from the switch to the Gigabit router.
As with any network, limitations arise from the cable distance. IP limitations are about 300 feet for data transmission and/or power. Without a repeater or booster in middle, you can at best achieve 300 feet distance. For further power you will need an Access point or bridge to boost wireless signals but this can actually help send signals over 9 miles distance from one access point to the other. Hence, for folks in remote locations where wiring is a major issue, IP Cameras with repeaters are an excellent option although you will end up sacrificing on full 1080p resolution.
As far as image quality goes, both IP camera and HD-SDI systems provide amazing detail and quality. While HD-SDI is usually of a higher quality it costs much more just in terms of equipment and initial setup cost, not to mention rewiring too. With IP Cameras, smaller the setup cheaper it is but larger setups usually require more investment into equipment. Regardless of the choice you make, resolution is at least 4 times better than analog CCTV systems.
If resolution, latency and all other things are taken to be constant, which is actually the case most of the time then IP cameras operate as individual sub-systems without any depot point hence they are much more reliable than HD-SDI cameras. Moreover, full digital IP cameras store data quicker and easier with better retrieval rates than analogue tapes. Wireless IP cams are definitely more cost effective and flexible as they can be used on buses, trains and moving objects or they can be used as part of an elaborate commercial security setup. The only true limitation with IP Cameras is when you use NVR and require a stable bandwidth or dependency on cables.