Bosch DINION XF LTC 0495 Installation guide

Q: What is the difference between NightSense and Day/
Night?
A: In NightSense mode, the camera turns off the DSP
color processing to achieve higher sensitivity (9dB more).
A Day/Night camera has an IR filter in front of the CCD
that switches automatically. The IR filter is necessary
for daytime color reproduction. Without the IR filter, the
camera can produce monochrome images – and it has
extended sensitivity because IR illumination (artificial or
background) is detected.
Q: If the application is not using IR illuminators, should
I use NightSense or Day/Night cameras? Why?
A: This depends on the presence of IR background
radiation. If there is no IR radiation, NightSense is the
preferred solution. If there is IR background illumination,
a Day/Night camera will generally provide higher
sensitivity and better images.
Q: What type of light source is best for good color
rendition, and how does that impact Day/Night camera
operation?
A: In Day mode, a Day/Night camera is the same as a
color camera. For both cameras, the best results come
from broad-spectrum white illuminators, such as halogen
spots. Good color reproduction is also possible with
incandescent and fluorescent illuminators.
Q: Why does IR light give an out-of-focus image (vs.
visible light), and is there any way to correct that
problem?
A: Focus differences between IR and visible light are
caused by the lens. The refractive index of the lens glass
light is different for IR illumination and visible light. Lens
suppliers (including Bosch) offer IR-corrected lenses
that are designed to avoid a focus shift in cases of IR
illumination.
Q: Do all lens types have IR-corrected versions, such as
fixed focal length, varifocal, and motorized zoom?
A: In practice, not all versions are available as IR-
corrected lenses. Bosch offers a range of varifocal and
motorized zoom lenses to cover the vast majority of
applications.
Q: Which type of filter is in the optical path during color
operation?
A: In color mode, the camera has an IR filter in the optical
path. This filter is necessary to keep IR background
radiation from falling on the CCD, since this would
prevent a good color reproduction.
FAQs for DinionXF Day/Night Cameras (LTC 0495 & LTC 0620)
Q: Which type of filter is in the optical path during
monochrome operation?
A: In monochrome operation, a “dummy” glass filter is
in the optical path. The sole function of this filter is to
make sure that the path length between the lens and
CCD is identical for color and monochrome operation.
Otherwise, there would be a loss of focus in either
operation.
Q: Can you explain the parameters that cause switching
from color to monochrome mode? (What level of IRE
or what percentage of IR scene illumination? Will it
oscillate between modes in certain conditions?)
A: In automatic Day/Night switching mode, the video
level is the condition for switching into Night mode. The
actual switching level (20 to 80 IRE) is adjustable through
the setup menu. Switching to Day mode is based upon
meeting two criteria:
The light level is above a certain threshold, which is a
fixed offset on top of the level for switching into Night
mode. The offset creates hysteresis to prevent oscillation.
Through the lens, the camera determines whether the
dominant light source is IR. If it is IR illumination, the
camera will not switch back to Day mode. The benefit
of this algorithm is that it will not oscillate, even when
strong IR illuminators are used.
Q: Will the camera go back to color operation if the IR
light level is high enough to generate full video 1 Vp-p?
A: The light level for switching to Day mode is a threshold
(a fixed offset on top of the level for switching into
Night mode – it’s needed to create hysteresis to prevent
fluctuations). The offset is approximately 15 IRE.
Q: How does the camera differentiate between IR and
visible light?
A: The camera runs an algorithm using the white balance
circuitry inside the Dinion IC to detect whether IR or
visible light is the dominant light source. (White balance
circuitry is available since the camera is in monochrome
mode, and white balance operation is not necessary.)
Q: What is the best wavelength of light to use when
selecting an IR illuminator?
A: The closer the infrared is to visible light, the higher
the camera’s sensitivity. However, visibility of the light or
light source to the human eye is also possible. Since IR
illumination ranges from 780 to 900 nm, a light source
in the 800 nm range usually provides the best of both
worlds.

Q: What is the highest wavelength of IR light I can use
with the Bosch DinionXF Day/Night camera?
A: 920 nm
Q: Can IR light damage the imager if a bright source is
in the field of view?
A: No. Reflected IR radiation is always at a safe operating
level.
Q: What percentage of nighttime light is in the IR
spectrum?
A: At full moon (and depending the moon zenith), about
seven percent of the total radiation is in the IR spectrum
between 780 and 900 nm.
Q: What is the advantage of using the 1/2-inch imager
over the 1/3-inch imager?
A: The 1/2-inch imager is more sensitive and, depending
on the quality of the lenses, its image contrast and
sharpness can outperform a 1/3-inch camera.
Q: What impact does IR light have on the camera’s wide
dynamic range?
A: IR illumination itself does not change the wide dynamic
range. However, the reflection of IR light is different from
the reflection of visible light for most materials. When
the IR reflection is about equal for all objects in a scene,
it can cause images with less contrast. The DinionXF Day/
Night camera offers the option to enhance the contrast
in Night mode – delivering the full benefit from wide
dynamic range behavior even in IR illuminated scenes.
Q: Can IR light be used to improve camera vision in
foggy scenes?
A: With the DinionXF Day/Night camera in Night mode,
exceptional images can be produced even in clubs and
restaurants where the camera is looking through smoke.
Q: Which version of Bilinx software is required to
operate the Dinion Day/Night cameras?
A: V2.20 and later are fully prepared for the Day/Night
cameras.
Q: What is 15-bit technology and why is it important to
me?
A: DinionXF 15-bit technology increases the accuracy with
which it processes the signal coming from the CCD. The
camera can process the signal to reveal details in the
dark and highlight parts of a scene simultaneously (due
to increased dynamic range). Increased accuracy also
leads to better color reproduction. Most CCTV cameras
are limited to 10-bit – so DinionXF 15-bit technology is,
therefore, 32 times more accurate for signal processing.
Q: How does the camera switch from day to night
mode (automatic, alarm input, Bilinx, profile mode
switching)?
A: Users can choose the method. The camera can switch
itself in automatic mode, but it can also be set up with
different modes (profiles) for daytime and nighttime
operation. Profile switching can be controlled via Bilinx
or the camera’s alarm input. The alarm input can also
be programmed to control Day/Night switching without
changing the profile. Of course, Bilinx can be used to
trigger the switching as well.
Q: Are the switching levels for Day/Night mode
adjustable?
A: In automatic Day/Night switching mode, the video level
is the condition for switching into Night mode. The actual
switching level (20 to 80 IRE) is adjustable through the
setup menu. The light level for switching to Day mode is a
threshold (a fixed offset on top of the level for switching
into Night mode that is needed to create hysteresis to
prevent oscillation). The offset is approximately 15 IRE.
Q: IR-illuminated scenes sometimes appear dull, and
don’t show enough detail; is there anything to help
restore contrast?
A: In Night mode operation in an IR-illuminated
environment, the DinionXF camera offers the option to
enhance contrast. This prevents images from looking dull
and flat.
Q: My monitor is still showing a monochrome image and
the camera switched back to color mode; how can this
be resolved?
A: When going from Day to Night mode, some monitors
have difficulty if the camera switches the color burst off
and on. The DinionXF Day/Night camera offers the option
to have the color burst in the signal during Night mode
also (Mono Burst ON).
Q: How many years of operation can I expect from the
DinionXF Day/Night IR switching mechanism?
A: The IR switching mechanism is specified for 15,000
cycles (approximately 20 years of continuous camera
operation) with one switch to Night mode and one switch
to Day mode every 24 hours.
Q: What is the function of Auto Black and XF-dynamic?
A: Both ensure optimal contrast reproduction in
weather conditions such as fog, rain, and snowfall. The
combination of functions lets the camera fully exploit its
dynamic range capabilities, thus revealing all of a scene’s
details.
6/2005 DINIONXF DAY/NIGHT FAQ