Manual
www.acti.com
  Firmware User’s Manual V6.09.45 
77 
Slowest Auto Shutter Speed is the user defined threshold for slowest allowed speed of auto 
shutter.  For  example,  if  by  default  the  shutter  speed  would  vary  between  1/5s  ~  1/2000s 
depending on the lighting conditions, then setting the Slowest Auto Shutter Speed to 1/30s would 
narrow down the auto shutter range to work between 1/30s ~ 1/2000s. The purpose of allowing 
user to define the threshold for slowest speed is to avoid motion blur caused by too slow shutter 
at night. 
It is also important to know that very high shutter speed is not recommended for indoor solutions 
with  artificial  light  that  flashes  with  certain  frequency,  as  it  may  produce  flickering  effect, 
regardless of Exposure mode. 
In extreme low light conditions, the shutter speed is slown down to get more light into one image, 
but not slower than the user defined threshold.   
If the exposure time extends beyond the interval between frames (too slow shutter), (i.e. 1/30 
second), then the frame rate will be automatically reduced.  Longer time in this value gives 
clearer images at night for slow moving objects, but more motion blur for fast moving 
objects.   
Exposure Mode - Manual 
When the lighting conditions are stable 24 hours a day, the advanced users may consider using 
manual exposure mode, to further fine tune the image quality in order to fulfill the special project 
requirements. Please note that in most cases, it is highly recommended to keep the camera in 
Auto Exposure mode and let the intelligent system of the camera find the best possible exposure 
settings instead. 
In  manual  exposure  mode,  the  user  can  directly  manually  adjust  the  signal  Exposure Gain, 
Shutter Speed, and even on select models, the IRIS Control (I-series zoom cameras only). 
NOTE: WDR is disabled in manual exposure mode (see Image on page 72).     
After  changing  any of the  items  above,  press  Apply  to save  the  changes.  The  Reset  button 
undoes the changes that had just been made but not Applied yet. 










