What our experts say…
We’re always a little wary of surveillance products that are described as ‘Intelligent’; the odd allusion to a particularly clever feature or fancy bit of circuitry you can just about get away with, but Sony has gone completely overboard with the SNC-DF50 network camera.
According to the publicity blurb this ‘Intelligent’ compact camera, part of Sony’s ‘Intelligence Range’, uses ‘Intelligent video analytics’ with ‘Intelligent built-in camera functions’ for ‘Intelligent Motion Detection’ and ‘Intelligent Object Detection’, and for good measure there’s ‘Intelligent automatic image recording’.
Quite so, but as we will see there are one or two aspects of the design that suggest a certain lack of savvy. First let’s see what’s under the bonnet.
The flowery terminology continues with a 1/3-inch, 440k pixel CCD using DynaView Technology for an improved dynamic range. This translates as capturing each image twice – combining dark areas at normal shutter speeds and bright areas at higher speeds. Low light sensitivity is down to 0.7 lux (0.35 lux with AGC on).
Sony’s Distributed Processing Architecture (DEPA) encompasses the sophisticated motion and object detection systems, and the rules governing alarm activation and recording.
It supports three compression codecs, providing moving video at up to 25 frames per second. They are: JPEG for high quality stills, MPEG-4 for moving video and H.264 for networks with limited bandwidth. Additionally it can generate JPEG and MPEG-4 images simultaneously. The camera, which lives inside a ball-shaped housing, can rotate, pan and tilt freely in any plane. It’s fitted with a variable focus lens that has a 3.6x optical zoom giving viewing angles of 27.2 to 100.8 degrees.
Other features include an image stabiliser, email notification, it has a privacy mask function (though this requires an extra software download), it supports uploading images to an FTP server and images can be viewed by up to 20 clients, using a standard web browser (Internet Explorer only). It can record video and still on its internal memory and these can be alarm activated or scheduled at preset intervals and there’s a voice alert facility – more on that in a moment.
The base section is quite thick, though, giving it a fairly chunky appearance but this is mostly due to a deep well in the base where all of the sockets have been grouped together. These include a standard LAN socket, a six-way spring terminal for the alarm I/O connections, a two-pin socket for the 12v DC/24v AC power connections, two jack sockets for an optional microphone and speaker and one of two composite video output connectors for local setup on a monitor (the other one, a phono connector, is inside the dome).
The top section is mostly taken up by the unusual camera mount, which is fixed to a single circular PCB. The camera module is housed inside a spherical enclosure and this is clamped between two cups, allowing the camera to be moved in almost any direction and orientation, then locked into position.
However, this is where we discover a design flaw. In a ceiling mount configuration it’s not a problem, but if for any reason the camera needs to be wall mounted, or inverted (dome uppermost), then the module has to be rotated through 180 degrees and a small locking arm on the lens – for setting and locking the optical zoom and focus adjustment – gets in the way and prevents the camera from being tilted downwards to its lowest possible position. The arm is awkward to get at and the focus adjustment is also quite tricky because it is so coarse.
Setup and operation
Basic installation and setup should pose no difficulties, though there is a vast range of secondary options, and working though the camera’s higher functions can be very time consuming, especially if there’s a requirement to delve into the darker recesses of the alarm setup, FTP server and wide area network configuration.
Once connected to a network by Ethernet cable, a utility program supplied on CD locates the camera’s IP address. Once obtained the camera is accessed via a web browser. Sony has made life a little difficult by only making it compatible with Internet Explorer; other popular browsers may not work properly. Firefox, for example, has problems with some of the plug-ins and cannot display MPEG-4 images. Normally this wouldn’t be a problem but our sample, admittedly an early demo, had a tendency to crash IE7 running under Windows Vista. Hopefully this will prove to be a minor bug, or just a glitch with Vista, and it can be swiftly resolved.
The main viewer screen gives a choice of 640 x 480, 320 x 240 and 160 x 120 images and there’s a simple one-step digital zoom (though this is another feature that doesn’t work in Firefox). A capture button takes a screen grab that can be saved as a JPEG file and a Settings button leads to a Password protected set of tabbed menu and sub menu options.
System covers camera name and title, serial number, date and time adjustment, reset to factory defaults, System and Access Logs. The Camera menu covers image mode (field/frame), switches for colour/mono, the image stabiliser, basic exposure and picture settings, microphone volume and audio codec, video codec and configuration, image size, frame rate, image quality and streaming setup.
Network deals with IP and submask setup, DNS server, HTTP port and IP address setup for email notification.
User and Security menus determine who is allowed to access the camera, and these are followed by sub menus for configuring email and FTP client setup.
The image Memory menu is for managing the camera’s on-board memory, alarm and interval recording. The Alarm Output tab is used to set alarm duration and timer schedule. Voice Alert enables one of three user-recorded audio messages that are heard through a speaker connected to the camera when the alarm is triggered.
The Trigger menu sets alarm actions and on the Schedule tab there’s a set of sub menus for programming activation of email, FTP, Image Memory, alarm Output and Voice Alerts.
Alarm Buffer activates pre and post alarm recording and finally, the Object Detection tab configures the motion detection and Moving Object detection systems. The latter is a clever extension of motion detection that can be programmed to recognise objects that are either removed from the scene, or placed in the field of view and abandoned or left unattended for a preset period.
Performance
Sony has a good track record in IP camera technology, so the rather lacklustre video performance of the DF50 is even more of a disappointment. Picture quality is simply not very good and some of the blame can be laid at the door of the lens. Obtaining a sharply focused image can be difficult to achieve due to the lens’s fiddly and coarse adjustment, and in an attempt to achieve a wide angle of view there’s a lot of barrelling in the image; the edges of the picture also look soft and this really shows up when objects and surfaces are close to the lens. The dome cover is clear and produces a lot of internal reflections, more than we’ve come to expect on domes of this size, though it’s possible a simple tint would help.
However, it’s the limited range of exposure controls, and non-existent colour balance adjustment that really lets the side down, and this applies to JPEG and MPEG-4 codecs, all quality settings and frame rates. The CCD image sensor is a capable design and there’s a fair amount of fine detail in the image but it suffers quite badly when there are bright lights in the scene – there’s no backlight compensation.
Colours appear washed out and dull and accuracy is not very good either, especially in changing or mixed lighting conditions. On the plus side low-light sensitivity is quite good and noise levels are very low. Physical stability is okay and it passed the SI rubber mallet test without any problems.