The Fraunhofer CAMSYS consists of a DALSA Turbosen-
sor camera and PC interfaces for camera control and data
transfer from a 64 MB RAM frame storage to the PC hard-
disk. Optionally a camera with 256 x 256 pixels and 200
images per second or a camera with 128 x 128 pixels and
1000 images per second can be used. By skipping lines the
temporal resolution can be increased to 3200 images per
second (256 pixel version) or 6400 images per second (128
pixel version) at constant data rate. Like with the Ektapro
EM the maximum sequence length is limited to about 5
seconds by the RAM capacity.
Besides linear array sensors with data rates of up to 120
MHz DALSA does also offer some more area cameras with
32 x 32 pixels, 64 x 64 pixels (3000 frames per second) or
512 x 512 pixels (60 frames per second), all with camera
data rates of 16 MHz. DALSA does not offer any storage
devices, so that the compilation of a complete system has to
be solved by the user.
EG&G Reticon offers some interesting cameras and sys-
tems with imaging rates ranging from 100 images per sec-
ond up to 15,000 images per second. The Reticon sensors
are photodiode array types with a non-interlaced output.
The MC9000 series area cameras are available with a 128 x
128 pixels sensor (380 images per second) or a 256 x 256
pixels sensor (105 images per second) and have been used
by scientists extensively (e.g. Dahm et al., 1990). With data
rates of 8 MHz they do not belong to the fastest cameras
today. The MC4256 (Figure 2) is a new fast framing cam-
era which integrates directly into a PC. It comes with the
same 256 x 256 pixels photodiode array as the MC9000,
but by parallel read-out with 8 read-out ports an imaging
rate of 480 images per second is achieved. The companion
AT-bus interface provides complete camera control and a
64, 256 or 1024 frame memory, which corresponds to a
maximum sequence length of 1/8, 1/2 or 2 seconds.
Figure 2: MC4256 camera with PC interface board
Highest frame rates can be achieved with the MC6464
camera (Figure 3), that can produce analog video at 15,000
frames per second from a 64 x 64 pixels sensor with 32 par-
allel read-out ports. The companion control unit produces
12 bit digital video at 7500 frames per second.
Figure 3: MC6464 camera
All these PC based systems with RAM storage are limited
in their storage capacity as the RAM on board can not be
arbitrarily extended and the write rates to standard hard-
disks are generally too small. An alternative to RAM stor-
age is the storage of image sequences on realtime disks
(RTD, sometimes also called videodisk). RTD systems
come as parallel transfer disks (one disk with multiple write
and read heads) or - mostly - as parallel disk arrays (Figure
4) and a controller distributing the data over many single
disks. The most powerful systems available today offer
data rates of up to 292 MB/sec and 672 GB of total capac-
ity. Disregarded the cost such a system can be an ideal stor-
age device for longer image sequences, if it can be
interfaced to a high-speed camera.
ET
US
aii digital
parallel
disk
Figure 4: Parallel disk array - principle
3. Multiple sensor systems
A relatively simple method to reach high imaging rates is
the sequential read-out of more than one sensor. To the
authors knowledge there is no such multisensor system
commercially available on the market, but if the task allows
to accept some handling problems one can relatively easily
design a powerful scalable high-speed system by simply
cascading standard CCD cameras. If one uses for example
16 CCD cameras with 50 ficlds per second each (CCIR)
and a shutter time of 1/1000 sec or less and synchronizes
them phase-shifted in a way that the integration times do
not overlap (Figure 5), one can achieve an imaging rate of
800 images per second at a resolution of e.g. 756 x 287
pixels (Sony XC77 or relatives). This corresponds to a data
rate of 175 MHz, which is far beyond the data rate of any of
the systems mentioned above. Working with full frames is
not possible here as electronically shuttered cameras do
