WebCams on the cheap
I
have been singularly disappointed with the quality:price
ratio of just about every web-oriented camera I have seen. For example,
I have a D-Link DCS-900
IP cam which I bought cheaply second-hand. While it does the job, the
image quality is fairly poor. I guess it's not really aimed at my
particular purpose, but if I'd paid full retail price for it I'd have
been pretty disappointed. I decided I needed to make something either
better or cheaper. Better has eluded me until recently, so I went for
cheaper in the interim.
The first prototype
I
bought a 'refurbished' Logitech QuickCam Pro 4000 USB WebCam
for
about $50.00 on eBay (which was pretty cheap back in 2005). I then
set about constructing a suitable outdoor housing for it. I used a
short section of 100mm PVC sewer pipe with a glue-on cap on one end and
a screw-down inspection cover (with O-ring seal) on the other. I cut a
circular hole in the centre of the cap and glued a piece of window
glass over it using silicone sealant so the camera could see out. A
short section of pipe cut at an angle and split to enable it to stretch
around the end cap made a handy shade hood. In the inspection cover
end, I drilled a large enough hole to get the USB plug through, then
slipped a rubber grommet over the cable to seal the hole against the
elements. A bit of silicone between the cable and grommet helped here
too. I used a strip of malleable metal to fashion a mounting base
inside the tube. I made its diameter slightly larger that the pipe, so
it holds in place by 'spring' pressure against the inside and meant no
holes had to be drilled to mount the camera.
USB issues
Of course, the DCS-900 connects via the local area network, so
the camera can be located anywhere that cat5 cable can be run. The
QuickCam Pro, on the other hand, is a USB device, so is limited to
about 5 metres. This was fine while I had the camera mounted under the
verandah roof outside my study window, but not much use when I
wanted to move the camera onto the peak of the roof (about 15 metres
away by cable) for a better view. The answer to this was an Icron
Rover
USB extender. These little gadgets allow USB devices to be connected
over vast distances (up to 100m) using cat5 cable. Fantastic, but at
nearly $300 they are not really in the 'cheap' category. eBay
to the rescue again, and I got a brand new set for $80.00 - a relative
bargain, but I had now spent more on the 'cheap' camera than on the
DCS-900! Still, the combination works flawlessly (within the
limitations of the camera lens), so I can't complain. And the rover
will have other uses later.
Software
Numerous webcam-capture packages are out there, but I wanted something
light and simple without all the bells and whistles. A freeware
programme called
FWink
(written by Canadian Chris Lundie) proved ideal. It is set to take a
photo every 5 minutes, overlay the text and upload to the web site via
FTP as well as saving a local copy. The Windows XP task scheduler is
set to start it at dawn and shut it down at dusk. The only intervention
required from me is to adjust the start/stop times every month or so as
the day length changes. I use the (free) personal edition of
URobot
to grab each image and rename it according to time of capture,
so they are all ready to be made into movies each night.
The movies
Another freeware programme called
JPGVideo
compiles the days images into an AVI movie every night at 9:00
(courtesy of the task scheduler again). These in turn are renamed with
today's date using a command-line utility called
namedate
by Swiss programmer James Green. The
xxcopy
utility then copies the most recent movie to a
webdrive,
which acts to map the webpages' FTP site as a local network
drive. Next, the Microsoft forfiles utility (from the old NT resource
kit) deletes any movies older than 7 days from the webdrive/server so
that I don't exceed my disk space allocation. Finally, the
now-redundant JPG files are deleted ready for the next days photos. All
this 'scripting' is done in a good old MS-DOS batch file. The only paid
software in the process is the webdrive, and it's worth it for the
flexibility that it affords in managing files on remote FTP sites. It
allows the old command line utilities to operate just like they were
acting on a local drive, plus it makes maintaining the website a breeze.
Weatherproof enclosure?
Over summer, I noticed some condensation was starting to fog up the
glass window on the camera enclosure. When I opened the case, there was
about 2mm of water lying in the bottom of the pipe. I'm not sure if it
was accumulated condensation or had been driven in by recent storm
rains. Either way, it was a problem. I dried out the puddle, but there
was still condensation present that couldn't be removed without
wrecking the camera alignment. I tried a little pack of silica gel
dessicant, but that failed to have any impact two days later. I ended
up stuffing one of my baby daughters nappies (diapers) in the back of
the housing (unused, of course) and the fogging was gone by that
afternoon. I suppose the annual maintenance will now include changing
the nappy as well as brushing off the spider webs!
A new webcam?
For all its reliability and simplicity, the Webcam Pro is really not
designed for capturing landscapes in any sort of detail or quality. It
has trouble with the high contrast of the outdoors, and streaks are
common on bright, cloudy days. There are now a growing number of
webcams based on old Olympus digital cameras. The first one I saw was
set up by
Ben
Quinn in Brisbane, and I was very impressed with the quality.
The guys at
EVS
in the US have kindly supplied their software for free. I have bought a
cheap used Olympus C-700 ultrazoom camera, which is supposed to work
under computer control, but so far no luck. My C-750 works great, but
it is still in daily use so I am not prepared to sacrifice it to webcam
work! This one is a work in progress ... watch this space!