In these days where there seems no alternative to digital IP cameras, it is understandable that many have assumed analogue cameras as an anachronism. It is perhaps surprising, then, that DeepSea has added analogue interfaces to its IP Apex and IP Optim SeaCam 4K cameras.
So what benefits do analogue systems still provide?
“We actually sell more analogue than digital cameras, although it’s just beginning to tip towards digital,” said Steiner. “If anybody is designing an ROV today, they probably won’t look at analogue cameras, but there is still a lot of legacy infrastructure out there. “In situations where video requires being transmitted over a longer cable, the digital options are pretty limiting. You don’t really want to put in a fibre where you can put in a coaxial cable. “In many cases, analogue cameras can be smaller, typically because the technology is more mature and can be miniaturised more easily than the digital IP cameras or SDI type cameras.
“Users say that it is still hard to beat some of the sensitivity of high resolution analogue cameras,” continued Steiner. “Of course you don’t get the same level of detail –our highest resolution analogue sensor is about 700 TV lines, but for the right application that’s not necessarily a problem. It is generally very simple to integrate, and a lot of systems and vehicles still have analogue architecture built in. “Analogue systems have a more square frame as opposed to the wide frame video common to HD video images. These are often more appealing to pilots who can get a better understanding of the view they are seeing.
“Analogue signals can travel much further than digital signals, possibly thousands of feet, although to do this, there are trade-offs, particularly in colour information. “Because it’s still an analogue signal, there is often a loss of some of the high frequency content and this has colour information.” Providing the IP Optim and IP Apex Cameras with an analogue interface is designed to improve the flexibility of these 4K camera assets.
“Our 4K cameras have about a 70deg field of view compared to the 170 deg perspective from our Super Wide-I SeaCam. Switching over to the analogue feed provides a different perspective, but all over the same interface. From a practical viewpoint, the main camera streams 4K images over the Internet. It has room for more than one bulkhead interface, and this makes it simple to add the secondary analogue camera.
“The camera interface allows a system designer to incorporate an auxiliary video source that can be streamed via h.264 or h.265 over Ethernet in addition to the internal 4K video feed,” said Steiner. “This means that the camera can be added without the need for additional multiplexer channels, making it possible to include wide-angle context cameras, tooling cameras, or low-light video on the same IP video interface that streams live 4K video. Switching between the video sources is done through the web-based user interface in just a few clicks.
In addition to the auxiliary analogue camera input, a virtual RS-485 COM port has been added, which can be connected to external smart devices such as the LED SeaLite LSL-2000 family of luminaires. The demonstration unit included a total of four smart lights connected to the IP Apex in addition to an analogue camera. Using the IP Apex or IP Optim SeaCam as a communication hub allows for a constellation of lights or other networkable RS-485 devices to be operated from a common interface in real time.