feature
THE EVOLUTION OF VIDEOWALLS
Up until the early 80’s multi-image displays
consisted of banks of slide projectors
synchronised to a sound track. While this was
a very effective and artistic way of displaying
multiple images on a single screen, it was very
expensive, cumbersome and required a lot of
maintenance. “Virtual”movement or animation
could be achieved using a large number of
slides and clever programming, but it was not
quite the same as video. However, this was the
only practical and affordable way of achieving
a big, dynamic image.
In the 80’s video projection was in its infancy and
was based on cathode ray tube (CRT) technology.
The biggest challenge with video projection at
the time was brightness: a typical CRT projector
could achieve only about 600 to 800 lumens. This
meant that projected images were limited to
about 4 meters in width, and required a darkened
room.
by Bruce Genricks (Managing Member)
CRT television sets as the displays. The TVs
were modified to accept RGB video and fitted
in custom designed sheet metal cabinets. The
steel cabinets served three main purposes: they
allowed the TVs to be stacked; they reduced the
image to image gap; and, they provided electromagnetic shielding.
Some of the early challenges faced by the
technicians were matching the colours across the
displays and aligning the images. Colour purity
across individual screens was a problem, due to
the magnetic effect of adjacent monitors.
Needless to say, the whole system was bulky,
difficult to set-up and very sensitive.
Video projectors
Monitors and television sets also made use of
CRT technology and were limited in size to about
70cm diagonally. In order to overcome these
challenges innovators in the industry started
“lacing” projectors or monitors together to
achieve bigger images.
By 1985, after the introduction of the videowall
processor in South Africa, events companies
started making use of arrays of video projectors
as displays. These usually consisted of CRT
projectors mounted in custom frames projecting
onto rear projection material. This was followed
by purpose-built projection cubes which
utilized mirrors and rigid rear projection Fresnel
screens. They were also designed to stack and
were specially mechanized to help with image
alignment.
The first multi-image video displays
Hybrid walls
In 1985 the first multi-image video displays
consisted of two or more projectors (or monitors)
projecting side by side onto the same screen.
A typical setup would consist of two videotape
recorders, synchronized via time code. One time
code for the left hand projector and one for the
right. In order to shoot the material for this setup,
two cameras mounted side by side would be
used. Although other methods of splitting the
image could also be used, this was the favoured
method as it retained the full resolution of each
image. By 1987, video tape recorders were
replaced by video disc players, and by 1996 by
DVD players.
The introduction of the videowall processor
In the mid 1980’s the first true videowall
processors were introduced to the audio visual
world. They consisted of large racks of eq V??V?@?6???V7FVB'??WG&W2?b?V?F?6?&R6&?W2?&V6W6P?F?W?6?V?B?????F?R7F?F&B??"?E40?&W6??WF???2F?W??BfW'???FVBgV?7F????G???G??6????F??r???WF?f?W"6??V?F?V?W0?f?FV???WG2??vWfW"?F?W?vW&R6&?R?b??6?VF??r&6?0?f?FV?VffV7G2?BvW&R&?RF?g&VW?R???vP?W"F?7???f?FV?v??????F?'0??????RW'?6R?'V??Bf?FV?v??????F?'2F?B??@?W??7B???7FVB?F?Rf?'7Bf?FV?v??W6VB??F?f?V@????F?RV&??V'2&WGvVV???RF????bf?FV??v??2?f?FV?&??V7F????B?V?F???vR6?FP?&??V7F???vW&R6??WF??W2??VB?F??2v0?W7V6???W6VgV?6??6R?&vR?V?&W'2?bf?FV??&??V7F?'2vW&R??Bg&VV?f??&?R?F?R&W6??WF???&Wf??WF???V&?f?FV?v??2?BGv????&?&?V?3??&W6??WF?????Bv?FR&Vf?6?W"??F?R&W6??WF????bF?RV&?f?FV?v??v2&6V@?????"?E427F?F&G2??BF?W&Vf?&R?B?????V?&W6??WF????bc#REb??W27&?72F?P?V?F?&R??vR?F??2?FR?B???7B???76?&?RF??6VR??FWF??v?V??v??f?VB7&?72?V?F??P?F?7??2??v?FR&Vf?6?W"?67W'&VB2&W7V?B?bF?R6??p?&Vg&W6?&FR?bF?R??vR?#Rg&?W2W"6V6??B???v???RF??2v26?v?F???????r??7F?F&@?FV?Wf?6???6WG2??B&V6?R&V?&?&?V?v?V??F?7??VB7&?72?&vR67&VV???BW7V6???6????F&?V?VB&?????F?Rw&??72&?6W76? ???F?RV&???w2f?FV?w&??72'&??dt??v2??G&?GV6VB26??WFW"w&??27F?F&B???B6???w&??2f?FV?v??&?6W76?'2f????vVB??F??2?Wr&??v?&W6??WF???"7F?F&B?v??6?@?F?B7FvRv2???cC?C???V?2??V?VBW ?v???R?Wr?&?WBf?"f?FV??"w&??2v??0?2F?W?6?RF?&R???v???Wr?6F???0??B$??r( 2f?W'F?V'FW"#0????6?VFVB6??G&??&???2?B????F?&??p?f6??F?W2v??6?G??6??F?7??VBw&??6??&W&W6V?FF???2?b&?6W76??r??G2?6??WFW ??"FV?W???R?WGv?&?2????R?bF?RGf?FvW2?bF?Rw&??2&?6W76? ?v2F?R&??G?F?F?7??F?ffW&V?B&W6??WF???2?@?f?FV?7F?F&G2?6??V?F?V?W6????F?R6?P?v????dtV?6??FWfV??VB??F?5dt??t?B6?????F?F?f?FV?v??&?6W76?'26?F?7????vW2?`?WF?F??B??B&W6??WF?????f?FV?v??7V&W0??f?FV?&??V7F?'2&?F?F?FVB?Wp?FV6?????v?W2??6?VF??r?V?B7'?7F?F?7????4B???B?FW"F?v?F??v?B&?6W76??r?D??FV6?????w???F?W6R?WrFV6???VW2???vVBf?"'&?v?FW ??BWfV?GV????v?W"&W6??WF?????vW2?F??0?FV6?????w?v26?????6?'?&FVB??F?f?FV?v???7V&W2?f?FV?v??7V&W2&R7V6???FW6?v?V@?&&??W2"v??6???W6RF?R&??V7F?"??'&?"?@?&V"&??V7F???67&VV??F?R?'&?"?2W6VBF?f??@?F?R?v?BF??F?W&V'?&VGV6??rF?R&WV?&V@?FWF??bF?R7V&R???F?W"???'F?BgV?7F????`?F?R7V&R?2F?W?6?VFR??W?G&?V?W2?v?Bg&??&V6???rF?R&V"?bF?R67&VV??F??2??&?fW2F?P?6??G&7B?bF?R??vR?&?&?V?v?F?F?W6R?Wp?FV6?????v?W2v26?7B?b?v?W'6?????'F?7V? ?F?RW?V?6R?b??&W?6V?V?B????&FW"F??&WF??V??f?&?'&?v?F?W727&?72??F?7??2??@?v2?V6W76'?F?&W?6R??F?R??2BF?R6?P?F??R?D?&??V7F?'2?6?&WV?&VB6???"v?VV??&W?6V?V?G2??v?V?7FF?2???v?6??G&7B??vW2vW&RF?7??V@????4B&??V7F?'2f?"W?FV?FVBW&??G2F?W??7VffW&VBg&??&??vR'W&?"?"??vR&WFV?F?????GVRF?F??2D?v2F?R&VfW'&VB&??V7F????FV6?????w?f?"f?FV?v??7V&W2??&??V7F???7V&W2&R7F???&V??rW6VBF?F???F??Vv?F?R&VfW'&VB???V??F???6?W&6R?2??p??v?B?V?GF??rF??FR??TB??GVRF?F?R???r?? ??fR?b?TB?F??2?2'&?Vv?BF?R?fW&??6?7B?`??v?W'6??F?v?6?v??f?6?F??5%B????F?'2??7F??VBB?V?F?6???6P???