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center axis the faster the tangential velocity and the worse the blur
appears to be.
When setting the pulse duration in degrees, what you set
is what you
get. Refer to the image on the right for the difference between a 1°
and 5° (of rotation) flash duration.
There are two methods of adjusting the flash pulse width and hence
the brightness and consequently the blur. For setting Brightness see
Brightness (BRITE) Menu.
6.2 Brightness in Degrees of Rotation
Brightness can be set from 0.2 to 14 degrees out of 360. The higher
the setting the brighter the strobe appears to be but the more
blurred the target is. Optimal setting to stop motion is 1.8 to 3.6°. The
number of degrees is a proportional amount and remains constant
as the flash rate increases or decreases. The strobe automatically
calculates how wide the pulse width should be at different flash rates
to keep the blur constant—the faster the flash rate the narrower
the pulse width. The pulse width equals: (setting in degrees/360) x
(1/flash rate in Hz).
6.3
Brightness in Pulse Duration
Brightness can also be set to a fixed duration pulse in milliseconds.
The flash rate remains constant irrespective of the flash rate, thus as
the flash rate increases, the image will get brighter and more blurred.
NOTE:
There are two limits maintained by the strobe – the flash pulse
width can never be greater than 2.0 msec (milliseconds) nor can it
exceed 14° of rotation.
The strobe automatically adjusts the pulse width and rotation values
as the flash rate is increased or decreased to maintain the limits at all
times. For example—a flash rate of 600 flashes per minute (10 Hz),
14° of rotation represents a flash pulse width of 3.8 msec. The strobe
will limit this value to 2.0 msec or 7.3° of rotation (blur).
