Olympus i-SPEED, Инструкция по эксплуатации

Страница: 42 / 56

Understanding i--SPEED
40
i--SPEED
The Olympus i--SPEED provides an automatic white balance
which relies on the user placing a pure white reference (sheet of
paper etc.) in front of the camera, completely filling the field of view
and then pressing the WB Set button. When this is done, the
camera will sample the reference and reconfigure its processing
electronics to render this as pure white. The reference must not be
removed until the white balance is complete, so an on screen
message shows the status of the white balance process.
`
Lighting
The Olympus i--SPEED has been designed to remove most of the
difficulty associated with taking high speed video shots, but two
areas of critical importance still remain, lenses and lighting. In
many cases, most of the time taken when working with the
Olympus
i--SPEED will be used in setting up the lighting, framing
the shot and choosing the correct lens.
Earlier sections of this document have described how the shutter
time and speed setting of the camera dramatically increase the
requirement for light. The result of this is that most high speed
video applications require a large amount of lighting and this is a
common theme in the high speed video industry. As a rough guide,
most indoor shots require 500 to 2,000 watts of additional lighting.
This is traditionally provided by shining a few high power spot lights
on the target scene but, for smaller targets, the Olympus range of
industrial light sources and light guides provide ideal illumination.
Simply providing a large wattage of light is not suitable for most
applications. It is usually necessary to carefully focus and target
the light, so general purpose floodlights are not normally useful in
HSV work.
An illustration is given from the experience of the i--SPEED
development team. A car parts manufacturer wished to view a
rapid movement in the mechanism of a prototype seatbelt reel.
The scene was illuminated with several 1,000 watt garden
floodlights, but this was sufficient for only a few hundred frames per
second. The lighting was removed and replaced by a single
specialised 500 watt spotlight and this permitted operation at 1,000
fps. When faster operation was required, the spotlight was
augmented by an Olympus Industrial light source and liquid light
guide and this increased the operating speed to 4,000fps.
This example is included to show that the quantity of light is
significantly less important than the concentration of light. Olympus
representatives are able to supply specialised lighting which has
been selected to be suitable for most high speed video
applications.