EL-2800M-PMCL / EL-2800C-PMCL
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8.8.1 About P-Iris
New Elite Series EL-2800M-PMCL and EL-2800C-PMCL come equipped with P-Iris control as
part of the standard lens control function. The P-Iris system is a newly developed lens
control method designed to control the iris more precisely. Especially for video cameras in
surveillance applications utilizing megapixel CCD or CMOS imagers, it becomes a very
important factor to control an iris in order to achieve the maximum camera performance.
In surveillance applications, depending on shooting conditions, resolution and depth of
field are important factors. The iris is deeply related with these factors. If the iris
diaphragm is smaller, but not too small, resolution gets better and the depth of field is also
deeper. The P-Iris system controls the iris diaphragm precisely and maintains the best
image with the highest resolution and depth of field. P-Iris can also combine with gain and
electronic shutter to keep the appropriate iris position under changing lighting conditions
(ALC function).
8.8.2 Setting for P-iris lens being used
P-iris lenses use an absolute setting value control system and therefore, if the following
parameters are input, precise iris position control is possible.
8.8.2.1 P-Iris lens select
Select the lens used. At present time, the following two lenses are available for these
cameras.
P-Iris lens select
Description
Control step number
Open F value
LM16JC5MM
KOWA 16mm 2/3-inch
74
F1.4
LM35JC5MM
KOWA 35mm 2/3-inch
73
F2.0
8.8.2.2 Step max.
Iris control step depends on lens. The setting value uses the value stored in the camera.
Refer to the table above for the control step number.
8.8.2.3 Position
The iris position can be set between 0 to Step Max. 0 means to open the iris and Step Max
means to close the iris. The camera initializes P-iris control and acquires iris position
under the following conditions:
1) When the camera is powered
2) When the lens is selected in P-Iris lens select
3) If the lens is changed in P-iris lens select
8.8.2.4 Current F value
The current F value is indicated by using iris position information. This can be indicated
during auto iris operation. The relation between iris position and F value depends on the
lens used.
8.8.2.5 P-Iris Auto min. / P-Iris Auto max.
This function can set the control range when the iris is operated automatically. Auto max.
sets the limit when the iris goes open and Auto min. sets the limit when the iris goes
closed. Auto max. can be set to fully open but Auto min. is stopped at F5.6 as lens
performance typically degrades if the iris is closed beyond this point.
8.8.2.6 Auto Iris Lens Control Signal Output
If the auto iris lens is used, this parameter should be ON. This is common for all types of
auto iris lens.