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Functional principle of the joker² light barrier system
Copyright eltima electronic 2022
The open-shutter mode
Name:
open-shu
, Levels:
,
,
,
Default setting: 0 s
For some subjects, it is desirable to reduce the delay of the entire system to
an absolute minimum. This can be particularly important for photographing
bats with their erratic flight paths.
Because these animals are nocturnal, keeping the camera shutter open for a
longer period of time is possible if there are no other lights. If a bat flies
through a light barrier while the shutter is open, the flash can be fired directly
by the system. Since both the light barrier system and the flash have an ex-
tremely short delay (together usually < 0.3 ms), the travel distance of the bat
during this time is negligible. The bat will be photographed while still being
in the beam.
The open-shutter mode supports this strategy.
For the correct operation of the open shutter mode, the shutter speed
of the camera must be set to "bulb"!
range
unit
step
0- 99
s
1 s
Using the default setting, with the parameter value = 0 the open shutter
mode is off.
For values > 0 the mode is on. It can be activated for any of the outputs. The
value of the parameter specifies the time in seconds for which the shutter
will be kept open if the camera is not triggered.
Preparation: This mode requires connecting the speedlight to one output
(e.g., output a) and the camera (of which the shutter speed is set to “bulb”)
to a second output (e.g., output b).
The trigger for the speedlight output is set to an action mode or any of the
three light barriers. The camera output is set to the same trigger as the
speedlight output. Furthermore, the open-shutter mode is activated for the
camera output by setting the parameter to a value between 1 and 99 seconds
(e.g., to 30 s). This represents the time for which shutter of the camera is
kept open cyclically if no trigger is detected. It is a good idea, to set this time
to a value for which the sensor noise level is acceptable.
Process sequence: As soon as the light barrier system is switched to the
working level, i.e. after training process, the camera is released for the time
set in the parameter.
If, during this time, nothing flies through the light barriers specified as the
trigger, the release of the camera is stopped (i.e., the shutter is closed) and
after about 1 second (so the camera can save the image and reset the sen-
sor), the shutter is opened again for the set time.
If the light barrier is interrupted while the shutter is open, the flash will fire
and a few moments later the release of the camera is interrupted and the
camera can save the image. After about 1 second, the next release will take
place.
This cycle can (only) be interrupted by switching to the alignment level.
Copy function
Name:
copy
, Levels:
,
,
,
Values:
No
,
to a
,
to b
,
to c
,
to d
Default setting:
no
.
This function allows copying all of the parameter settings from one output to
another.