|
BENCH TEST --
PULNIX TM-520
MONOCHROME CCD
CAMERA
COPY
The Pulnix TM52
is by no means the smallest black and white camera on the market, but it is
undoubtedly close to the point where, if it were much smaller, the case would
no longer have enough room for a C/CS lens mount, standard-size connectors or
the fittings for a support bracket!
In fact it
could easily have been a lot smaller, judging by the amount of vacant space
inside the housing. The case of this British designed and built camera is not
much longer than a couple of standard lenses, placed end to end, and only a few
millimetres wider than the lens barrel. The actual dimensions are 45 x 39 x
92mm and the all-up weight, excluding any lens is a mere 235 gram's. Inside the
three circuit boards (PSU, signal processing and CCD), are populated by a
handful of chips and predominantly surface-mounted components. This type of
construction should ensure maximum reliability, and immunity to mechanical
shock or vibration. Pulnix's own tests have involved putting the cameras through
shock and vibration cycles for up to nine hours. The manufacturers seem
reasonably confident about the camera's longevity and it comes with a 3-year
warranty.
The dark grey
case is made entirely from metal and whilst not fully weatherproofed is
well-protected against ingress of dust or moisture; a weather-resistant housing
(HO-500) is available as an optional accessory. Externally there are just three
sockets, a BNC connector carrying the video output, a 6-pin connector for the
lens and external shutter controller, and a 12-pin socket for, amongst other
things, the 12VDC supply and external sync signals, (if option specified). On
the front panel, made from cast alloy, there is a threaded metal collar for C
or CS type lenses. Pulnix market two 12 volt DC mains power supply units (built
to BS415): the DC12B has a maximum supply current of 500mA and is designed to
power a single camera; the DC12/240, is rated at 1.7A and can supply up to half
a dozen cameras.
There are no
external controls or user adjustments. Shutter speed (8-steps, up to 1/10000th
sec) can be set using a control module (SC745), or it can be varied
automatically, as an factory-fit option on the TM520. There are only two
internal adjustments, for ACG and gamma correction, both of which are pre-set
to on, and 0.45 respectively. As a matter of interest there are several
variants in the TM500 series, including the PE530 which shares a similar basic
specification to the TM520, but in addition has external switches for AGC,
gamma correction and shutter speed, and
an external sync facility is fitted as standard. The TM510 is a board camera,
fitted with a 0.3-inch interline CCD and fixed 4mm lens; it is designed
primarily for OEM use in security and imaging, and as such is extremely
flexible with provision to mount the CCD in a variety of positions, and connection to external
equipment via a ribbon cable. Incidentally, Pulnix will also consider custom
artwork or designs, as an option on all of their TM500 series cameras.
The camera is
supplied with a pair of 6 and 12 pin plugs, and not much else, apart from a fairly cursory specification cum
instruction sheet with pin-out diagrams for the two plugs. A complete manual is
available upon request. Pulnix can supply any type of lens to order, along with
a wide range of mounting hardware and enclosures. The average price for the
TM520 is around £280; the shutter and external sync options take it up to £350
or so. The better specified PE350 sells for £340 and the two power supplies
(DC12B and DC12/240) cost £12 and £50. The TM500 is the baseline camera in the
range, it has a similar specification
to the TM520 but a slightly lower-resolution CCD, though better low-light
performance (0.2lux at F1.2), it sells for around £180.
PERFORMANCE
The basic
specifications look impressive; the TM520 (and PE530) have an 0.5-inch
interline transfer CCD image sensor with a 752 x 582 pixel array and a stated
minimum sensitivity of 1 lux (F1.4); (Low light sensitivity on the TM510 board
camera is 0.5 lux at F1.4). Resolution is quoted at 560 horizontal lines, by
420-lines vertical. These figures were borne out in our tests which showed
horizontal resolution to be well in excess of 550-lines, and low-light
sensitivity comparable with similarly specified mono cameras. Generally
speaking image definition was very good, with a broad dynamic range giving
plenty of contrast, even in poor light conditions. Vertical edges are clean and
in good light noise levels are very low. Lag or comet-tailing was negligible;
some slight vertical striation became evident at very low light levels,
however, it was not sufficiently intense to be a problem
OVERALL
ASSESSMENT
Performance is
good and with the correct type of lens, this camera can be used in a broad
range of locations and site conditions. The small size carries no significant
operational penalties and the variants within the range cater for most
specialist needs. As it stands the TM520 is a practical general-purpose design
that can old its own, both in performance and cost terms, against cameras many
times larger, and costing significantly more. Whilst the TM520 isn't quite
small enough to qualify as a covert camera, it is nevertheless a very
unobtrusive design. Its small size and light weight can also be put to good
advantage in a number of other applications, including image processing and
machine vision, though the PE530 board camera variant may be better suited to
this kind of dedicated installation. An efficient and thoroughly well-designed
mono camera that fulfils a wide range of needs in video security and
surveillance, especially where space is at a premium, or a certain amount of
discretion is required
PRODUCT
ASSESSMENT
Design and
design features ****
Circuitry and
components ****
Ease of
installation and wiring ****
Range and
variety of functions ***
Accompanying
instructions **
Technical
advice and backup ***
Value for
money
****
---end---
© R.Maybury 1993 0111
|
