eltima electronic Jokie 2, User Manual

Page: 21 / 26

Taking pictures with Jokie²
Working with the sensitivity of the light barrier
As described in the section Sensitivity the latter depends
on the transmission power of the IR-sender, the working
distance and on the size of the reflector. This interrelation-
ship is shown in tables 1 to 6.
Taking pictures of small objects
In order to photograph small and smallest objects as for
example water drops, small insects or projectiles you have
to take a small reflector and switch the transmission power
of the IR-sender to the minimum, see table 1. To achieve
a high sensitivity you should position the reflector further
away from the light barrier if possible, but nevertheless so
that the LED will still go off reliably.
In case it should not be possible to place the reflector far
enough away from the light barrier, you can also obtain
the favored sensitivity by tilting the reflector to the side,
as you can see in image 21, until you get the sensitivity
you wish to work with.
Blanking out of smaller objects
When taking pictures of larger objects such as mammals,
it is normally preferable to avoid erroneous releases due to
flying insects or falling snowflakes.
For that purpose you need to take a large reflector, switch
the transmission power of the IR-sender on high or maxi-
mum, see table 1, and position the reflector, if possible,
quite close to the light barrier.
© eltima electronic 2013
21
Image 21: increasing the sensitivity