Nd Filter - ARRI ALEXA Series User Manual

198 ALEXA Studio

15.2.4 ND Filter

The ALEXA Studio has a ND filter in front of the sensor, which can be
moved in and out of the optical path. The motorized filter slider
contains a ND filter with a density of 1.3 (= 4.3 stops), and a cover glass
without additional density. The filter slider is sealed, so that no dirt or
dust can enter the area between the slider and the sensor.
Note: Perform regular dust checks on the outside of the ND filter slider, as dust
might collect on top of it. As the slider is very close to the sensor, dust or dirt
collecting on it might be visible as artifacts in images.
When performing a dust check, make sure the camera is switched off and
disconnected from any power source to prevent the mirror shutter from
activation during the cleaning process.
The ND filter can be activated in the EI screen by pushing the lower
right screen button.
Figure 114: EI screen
If activated, the ASA rating in the HOME screen will have an ND index
next to it.
Note: The use of the internal ND filter has no influence on the EI rating of the
camera. When measuring exposure with a light meter, take into account the
light loss of 4 1/3 stops generated by the ND filter.