A guide to investing in high-speed cameras
for crash testing
by Alan Neal, Managing Director,
Photo-Sonics International Ltd.
It is hard to foresee a time when safety will stop
being a key issue for the automotive industry. Vehicle manufacturers
continue to invest heavily in the development of improved safety features to
attract customers, while the need to comply with government regulations
gives ongoing impetus to progress in this area.
Nor is there likely to be any reduction in the key
role played by crash testing in the development of safer vehicles. Greater
reliance on computer modelling within the industry has not eliminated the
need to carry out real crash tests as part of the automotive R&D process. As
a result, demand for increasingly effective high-speed cameras capable of
recording crash test impacts will continue unabated in the years ahead.
Traditionally, film-based 16mm cameras have been the
industry standard. Recent years have seen the development of an alternative
in the shape of digital imaging equipment. Inevitably, some parts of the
automotive industry have been slower to embrace high-speed digital cameras
than others. One reason is lack of familiarity with the technology. Another
is the natural desire to await developments in what is a fast-moving field -
and to be sure that the technology has evolved to an acceptable stage of
maturity before committing investment.
The truth of the matter is very simple. The latest
generation of digital high-speed cameras offers high-quality performance and
a range of valuable benefits for organisations engaged in crash testing. Now
is the time to give serious consideration to investing in a digital imaging
system.
Weighing Costs and Benefits
Going digital can be a big step. Replacing traditional
high-speed cameras with state of the art digital equivalents will involve a
significant investment. It is vital, then, to be certain that you are making
the right decision. This means understanding - and quantifying - the
benefits that would result from the upgrade to digital imaging. It also
means developing a clear appreciation of how much can be achieved within
your existing budgetary constraints.
Along with ease of operation, the main advantage of
digital imaging technology is improved efficiency. Digital cameras generate
data that can be downloaded straightaway, enabling image sequences to be
viewed and analysed immediately after recording. Compare this to traditional
film-based cameras, where film needs to be developed - a stage that can take
several days if no on-site processing facility is available. Digital
imaging, then, can shorten the time from crash to quantitative and
qualitative analysis from days to minutes, with all the associated benefits.
It also removes film processing costs altogether.
Moreover, these benefits can be achieved without any
detriment to image quality. High-speed digital imaging technology has taken
important strides since it made its first appearance several years ago. In
particular, manufacturers have focused their attention on overcoming the
inevitable technical limitations of the first generation of equipment. As a
result, the latest generation of high-speed digital cameras are a factor
superior to their predecessors in the vital areas of both resolution and
sensitivity.
The level of performance that can be achieved
by a digital camera is largely a function of the sensor it incorporates.
Important technical advances have been made in this respect, such as the
development of CMOS sensors, which are incorporated in
NAC's series of digital cameras. The sensor has
been designed exclusively for high-speed use, and to provide the right
combination of sensitivity, high resolution and speed, without blooming.
This means that the NAC range can offer resolutions of 512 x 512 pixels
up to 1280 x 1024 pixels at frame rates of 50 to 200,000 pictures per
second (GX-1).
Assessing Your Needs
Once you have established that digital imaging could
provide you with cost-effective benefits, you will need to consider
precisely what equipment to invest in. The first step is to identify cameras
suited to the various crash test scenarios that you are likely to encounter.
Different digital cameras are designed with different applications in mind,
and so have different specifications and characteristics. Our view at
Photo-Sonics is that there is no such thing as a universal camera. For
example, a camera designed to record crash test events in the confined
spaces of a footwell or a car door will need to be significantly more
compact than a camera specified for off board use. The key is to ensure that
the equipment you invest in is fit for the intended purpose.
Although digital cameras can be operated on a
stand-alone basis, one of the great advantages of going digital is the
ability to control multi-camera systems from a single workstation. This
means you will need to make sure that your network, if you have one, is
compatible with your choice of digital imaging equipment. It also means that
your network will have to deal effectively with the huge amount of data that
the new high-resolution digital cameras generate if it is to deliver the
download times usually demanded. Existing Ethernet networks cannot cope with
these higher data rates, so for our new
NAC range we have incorporated
Gigabit Ethernet technology into the design. To
achieve maximum flexibility of operation, it is also important to ensure
that your digital camera network uses standard protocols.
Lighting is another key issue that is often
overlooked. Even more so than with film-based photographic systems, digital
cameras cannot deliver optimum performance if they are expected to operate
in an environment with obsolete or inappropriate lighting. Investing in a
lighting system can be a major commitment in its own right - in some
instances costing as much as the digital equipment itself. As a rule of
thumb, though, the more sensitive the digital camera, the more likely it is
to be able to work with existing lighting systems.
The lighting issue is a useful reminder that going
digital is not just a question of high technology. Although a significant
leap forward in technical terms, digital imaging is, in the final analysis,
a form of photography and the laws of physics still apply. Consequently,
photographic skills and expertise, e.g., an appreciation of issues such as
aperture, light and focus, are still required. The temptation to fall prey
to an "anyone can do it" mentality needs to be avoided.
Choosing a Supplier
Currently, the market for digital imaging equipment
suitable for automotive crash test applications is occupied by a number of
specialist manufacturers. When deciding which of these to buy equipment
from, here are four issues to bear in mind:
1) Backwards Compatibility. As noted earlier, digital
imaging is a very fast-moving field, with technical advances constantly
giving rise to the development of new, improved models. Sometimes this can
act as a disincentive to deciding to go digital, because of the fear that
equipment invested in today will be obsolete tomorrow. The key, then, is to
ensure that the supplier you choose offers backwards compatibility, which
will enable you to continue using existing equipment in tandem with any
advanced models or components that may become available and that you may
decide to buy.
2) After-sales Support. Clearly, there are significant
advantages if your supplier can offer you ready access to direct support and
servicing, avoiding the unacceptable delays that can result from sending
equipment a long way away.
3) Understanding. Always look for a supplier that can
show a genuine, hands-on grasp of all the technical and operational issues
related to the use of digital imaging equipment. In essence, this means
demonstrating substantial engineering expertise and applications knowledge.
4) Track Record. In digital imaging, as in so many
fields, there is no substitute for a proven pedigree. Ensure that your
supplier has an impressive track record and can demonstrate wide and long
specialist experience of the industry.
At Photo-Sonics, we build our offering around these
principles - and I'm sure our competitors would make similar claims. The aim
must always be to ensure that organisations make the right decision about
going digital, and then to help those that do to reap the valuable rewards
that can result. In this way, companies like Photo-Sonics can contribute to
the rapid take-up of digital imaging technology that is widely predicted for
the years ahead.
