Flk (Flickerless) On/Off Switch; Blc (Backlight Compensation) On/Off Switch - i-onyx VN-855 Installation & Operation Manual

mode selected, a fixed or manual iris lens can be used instead of an autoiris lens. In the AI/ALC
mode, the CCD shutter speed is fixed to 1/60 (NTSC, 1/50 PAL) sec, and the incoming light level
is controlled by the autoiris lens. When using a DC-drive type of autoiris lens, set this switch to the
AI/ALC position.
Cautions:
1) Under bright lighting conditions such as a sunny day outdoors, use an autoiris lens; the EE/ELC
control range is not wide enough under these conditions.
2) Under certain unique lighting conditions, the following phenomena may appear:
Strong smear and/or blooming on high light objects such as spotlights or windows.
Noticeable flicker in the picture and/or color rendition variations.
To avoid this, use an autoiris lens.
3) When operating in EE/ELC mode with a manual iris lens, the depth of field of the image may be
less than that obtained by using an AI/ALC lens. Depth of field varies inversely with the iris opening.
Thus, using this camera in ELC mode with the manual iris lens fully opened may result in less depth
of field and the distant objects in the picture may be seen out of focus.
Note: When adjusting the focus, it is recommended that the iris be completely open (a dark condition, either
at night or using a filter) so that the depth of field does not influence the adjustment.
4) Fixed iris or manual iris lenses may be used with the linear shutter (EE/ELC mode) when the
scene brightness varies over a limited range.
5) Do not use the EE/ELC mode when an autoiris lens is installed.

2. FLK (flickerless) ON/OFF Switch

This function is only used in Japan. When set to ON, the shutter speed is fixed at a rate of
1/100 (120) sec.
3. BLC (Backlight Compensation) ON/OFF Switch OR WDR (Wide Dynamic Range) ON/OFF Switch
(VN-855WDR only)
If the subject being viewed is too dim because of a bright background, set the BLC switch (Pole 3)
to ON to compensate for the bright background. With BLC on, the background brightness may
saturate in some cases. This function may not operate properly if the object is too small compared to
the area of the background. This function can be used with either the linear shutter (EE/ELC mode)
or an autoiris lens (AI lens/ALC mode). For the VN-855WDR, the Wide Dynamic Range (WDR) function,
which
provides the best contrast for high quality images,
5
can be turned ON or OFF.
XX181-02-00 Rev 1107 VN-855 Ver 3 IP Camera