Measurement methods
15
Example
Camera exposure time:
1/250 s
LED-Panel settings: CONTINUOUS, exposure time 1/10 s
Each time the LED has moved three places forwards between the consecutive images. With
LED-
Panel’s frequency set to 0.1s this means the multi shot mode has the speed of 0.3 s per
picture (i.e. 3.3 pictures per second).
4.6 Rolling shutter speed
The LED-Panel can be used in both, CONTINUOUS and TRIGGER EXT operating modes. In
TRIGGER EXT operating mode the LED-Panel is connected to a remote release and is started
using this switch. Because the two buttons have a different release point, a time lag can occur
between starting the LED-Panel and camera release. We have developed a device that pushes
both buttons (micro switch and camera release button) in less than 5 milliseconds guaranteed.
The so-called iQ-Trigger activates the camera release mechanically. The iQ-Trigger is available
as a separate product.
In the rolling shutter operating mode all ten rows of LEDs are operated simultaneously. This
means that a whole column of LEDs runs across the panel instead of single LEDs. Cameras
with a rolling shutter show an offset in the taken picture between the LEDs in the running
column. From this offset the time can be read, that is required for reading out the picture of the
LED-Panel.
For this measurement we recommend to frame the field of the LEDs in the image in such way
that they fill the whole image height.
Figure 11
In the rolling shutter mode all ten rows of LEDs
are operated simultaneously
Figure 11a
In case of a rolling shutter effect an off-set of
the LED rows is visible.
