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PRODUCTS & SERVICES
high-speed cameras
for aerospace testing
High-speed cameras facilitate the detailed analysis of projectile flights, missile
launches, combustion processes, engine performance, fuselage durability, material
strength, flow/particle movement and more – there are many factors to consider when
purchasing a high-speed camera – the most important of these are described below
The first consideration is frame rate. How
many frames per second (fps) are
required to capture sufficient image
detail to analyze a high-speed event? There
are a handful of camera suppliers who
provide cameras that run at speeds in excess
of a few thousand fps at megapixel resolution
or higher.
LIGHT SENSITIVITY
In certain applications light sensitivity is
the single most critical consideration.
Light sensitivity impacts the quality of highspeed
images because without
it the images will be dark and
difficult, if not impossible,
to analyze. Light sensitivity
is typically presented as an
ISO value. The higher the
ISO value, the more sensitive
a camera should be. There
are standards – such as
ISO 12232 – that define how to
measure light sensitivity, but
many high-speed camera
vendors do not adhere to the
standards when they measure
the ISO values of their cameras.
Some vendors publish ISO values but do not
specify which ISO standard
the values conform to. Without such
information the ISO values are meaningless.
MINIMUM EXPOSURE
Some very fast high-speed events require
extremely short exposure times – sometimes
even less than a single microsecond – to stop
the motion of those events. A camera’s
ability to achieve a sub-microsecond
exposure is dependent on two things. First,
the camera’s sensor must be capable of
performing such a short exposure. Secondly,
the camera’s sensor must be sensitive
enough that when it does use a
sub-microsecond exposure it can capture
enough photons of light to generate video
that is of sufficient quality for analysis.
DATA OFFLOAD
After the high-speed event has been
captured by a camera, the video data must be
transferred from the internal memory on the
camera to a more permanent location for
storage and analysis. Most camera suppliers
have chosen to implement some form of
Ethernet to enable the transfer of the data
from the camera. Because the recorded data
can be tens of gigabytes or larger in volume,
the data transfer over Ethernet can be a
bottleneck in getting the data out of
the camera.
As an alternative to Ethernet, some
cameras can download images at very high
data rates to a removable nonvolatile memory
source such as a high capacity removable
SSD. Recorded data can then be directly
accessed from the SSD while it is coupled to
the camera, or the drive may be removed
from the camera and inserted into a docking
station for image transfer to a PC.
SEALED CAMERA BODY
Certain testing environments contain large
quantities of airborne dust and other
corrosive particles. Some camera suppliers
DECEMBER 2019 \\ AEROSPACETESTINGINTERNATIONAL.COM
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have implemented a sealed body design that
prevents such contaminants from being
ingested within the internal camera body,
where they can adhere to and damage
sensitive electronics.
Aerospace testing environments can be
especially challenging for high-speed
cameras. Frame rate and light sensitivity are
typically the most important factors to
consider when purchasing high-speed
cameras, but as discussed above, there are
other things one should think about such as
minimum exposure time, data offload speeds,
and a camera body design that protects
sensitive electronics from contamination by
airborne particles. Photron’s new FASTCAM
NOVA provides impressive performance in
each of these areas.\\
FREE READER INQUIRY SERVICE
photron
1 // Still image captured
using Photron high-speed
cameras of space shuttle
Endeavour’s thrusters
2 // Two FASTCAM SA-Z
high-speed cameras were
used at Wichita State
University for DIC fuselage
drop test
3 // Photron’s FASTCAM
NOVA sealed body highspeed
camera shoots
12,800fps at 1024 x 1024
For more about this advertiser, visit www.magupdate.co.uk/pati
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/AEROSPACETESTINGINTERNATIONAL.COM
/pati