In it for the long haul

Times and markets change, technologies come and go – but one thing you can always rely upon is Mitsubishi making top-end video surveillance recorders. It seems like Mitsubishi has been building them since the year dot, so they must be doing something right.

Its VHS time-lapse machines were famously long-lived and somewhere deep in the Security Installer archives there's a Bench Test review, written in the late 1980s if memory serves, of a Mitsubishi surveillance VCR that had clocked up something like 50,000 hours use without a service. It was still on its first set of heads and the picture quality was almost as good as the day it was built.

Tape head wear is no longer an issue and it's amazing to think that we used to get quite excited about cramming more than 150 hours of fuzzy video on a three-hour tape. Nowadays recording times – not that such things are spoken of all that often anymore – are measured in weeks, or months, in the case of the Mitsubishi DX-TL4509 digital video recorder. In fact, with its full complement of internal and external storage, adding up to an impressive eight terabytes, this machine is theoretically capable of recording continuously for more than 18 months!

Behind that headline grabbing facility is a versatile, well-featured, high-performance 9-channel DVR (a 16-channel variant is also available). It's a triplex design that comes with 500Gb drive as standard with the option for a second drive and the previously mentioned 7-terabyte external storage unit.

It uses the increasingly popular JPEG 2000 compression system and resolution is 720 x 576 pixels (frame recording mode) at up to 50 fields/sec per camera. There's a choice of five quality (compression) settings with image file sizes ranging between 5 and 34kb, and the option of Field or Frame recording with the rate variable between 0.125 and 25 fps in 12 steps.

Behind the scenes everything is controlled by a Linux-based operating system, and the display options include single, quad, 3 x 3, sequential, covert and Alarm display. With the supplied network software it's possible to remotely view all inputs, search and playback recordings, access the DVR's configuration menus and operate PTZ controls.

It's evident from the hefty-looking case that there has been no attempt at miniaturisation or prettification. It's a purposeful looking lump of a machine measuring 425 x 353 x 128 and weighing in at 10.5kg.

Inside the case there's a sight to behold. The machine is built around a heavy-duty chassis, the layout is fairly conventional and apart from the mainboard and a couple of other PCBs most of the parts are standard off the shelf components, but what sets this apart form pretty well every other DVR we've seen recently, is the almost obsessive attention to detail. It is unbelievably neat and tidy. There are no loose cables flopping around. Transparent dividers support the cables that pass between the various boards and components, and they're perforated, to allow the free circulation of cooling air. Where cables pass through holes in the chassis there are plastic guards to prevent chafing. In short the standard of construction is of a very high order and it is clearly built to last.

Setup and operation

With its unrivalled experience in designing and manufacturing video recording equipment you would expect the TL4509's controls to be a model of clarity. Unfortunately that is not the case and unless you go to the trouble of installing a USB mouse (not supplied) navigating the on-screen menus is an absolute nightmare.

There appears to be no rhyme or reason to the design and operation of the OSD. To enter setup mode it is necessary to press a button under the hinged flap and from there on in choices are made using the row of display mode and PTZ buttons (lettered A to E) underneath the PTZ, with an occasional excursion to the camera selector buttons. On some menus you have to switch back and forth between the two banks of buttons. Even the most basic operations take forever. In short forget it and get a mouse!

Mitsubishi's DX-TL4509E nine channel DVR is a top performer – but beware of its menus…

Even with the assistance of a mouse the menus still take some getting used to. It's almost as if the on-screen displays were designed by two rival departments, who don't talk to each other. Entering setup mode displays a bar menu along the bottoms of the screen and after selecting (or clicking on) an item a pop-up menu appears, with items listed in reverse order and unlike a conventional PC type menu display they do not disappear when you have finished with them. Strangely the boxy pop-ups are in a completely different visual style to the softly rounded and blue-tinted menu bars. It gets worse; we won't bore you with the details but suffice it to say the person (or more likely committee) that designed the camera title setup clearly has sadistic tendencies. Once in setup mode you can step through three menu bars, which appear at the bottom of the screen. The first one deals with Search (by Time & Date, Alarm, Bookmark or Motion), Copy (to internal or external drives), Hard Disk Information, Protect Data options and PTZ control.

The second menu bar has options for Recording (per camera input frame rates & recording quality, Alarm and Emergency Recording settings), Timer setup, Motion Detector setup, System setup (reset, OSD settings, Multiplexer, Passwords, OSD menus) and Save Menu. Finally, on the third menu bar there are sub menus for Com/LAN settings, PTZ setting, Service Information, Restore/Copy drive information, Memory status and Clear Data.

Most of the menu options are reasonably straightforward, though inputting data and making changes is a lot harder than it needs to be thanks to the idiosyncratic design. Praise where it is due, though, and the Motion Detection system is surprisingly versatile and easy to use. It uses a 23 x 22 target grid so it can be set very precisely to ignore small or irrelevant movements, and there's a useful set of configuration settings, including five sensitivity settings, variable motion threshold and interval time, Test Mode and the facility to copy settings to other camera inputs.

One useful piece of information that could have been made more accessible is the estimated recording time, which is automatically recalculated after any changes have been made to the camera settings. This is buried deep on the Recording menu and whilst Alarm recordings are automatically protected, without this information it is possible that potentially important recordings could be inadvertently overwritten. In the end, however, the only good thing we can think of to say about the setup menus are that once the machine has been configured you rarely need to use them. The rest of the controls are much easier to live with.

Routine operations, such as setting display mode, camera selection and so on, are largely intuitive and simple to use. Switching from live monitor (Record) mode to playback requires a single button push and is more or less instant. The Search facilities, whilst fairly basic, are reasonably easy to use (with a mouse), the jog/shuttle dial provides a fast and accurate way to locate and review a section of a recording, and exporting a recording (with embedded PC viewer software) is very straightforward.

Network connections can be made via standard web browser (Internet Explorer) or supplied software. When using the former it is necessary to key in the DVR's IP address then enter the user ID and Password. A viewer plug-in is downloaded to the browser and it is ready to use. Options include live monitoring and playback of all connected channels and access to the DVR's configuration menu covering User Registration, setting Recorder and Camera Titles, email notification setup and clock setup.

Performance

In common with other DVRs we've looked at that also use JPEG 2000 compression, image quality is excellent. On the lowest quality setting (L1-5kb) it looks a touch ragged, but on the medium and higher levels (L4-22kb & L5-34lb) the picture reveals a lot of fine detail with strong vibrant colours and negligible noise or processing artefacts.Image stability is outstanding at all playback speeds and there is virtually no lag when changing speed or direction.

The single channel audio recording facility is set by default to camera channel 1 though it can be assigned to any of the other eight channels from the setup menu.

Audio quality is actually quite good, and whilst not exactly up to hi-fi standard it is nonetheless perfectly adequate for recording speech and the sort of incidental sounds picked up by camera mikes.

Mechanical stability is good, though because of the hard drive we couldn't subject it to the usual sound trashing from the SI rubber mallet. It didn't flinch when gently bumped or knocked, however.