User`s manual

Standard Features AW00089316000
270 Basler ace GigE
10.8.3 Considerations When Using Binning
Increased Response to Light
Using binning can greatly increase the camera’s response to light. When binning is enabled,
acquired images may look overexposed. If this is the case, you can reduce the lens aperture, the
intensity of your illumination, the camera’s exposure time setting, or the camera’s gain setting.
When using vertical binning on monochrome cameras, the limits for the minimum gain settings are
automatically lowered. This allows you to use lower gain settings than would otherwise be available.
For the lowered limits for the minimum gain settings, see Section 10.1 on page 209.
Note: The vertical binning of the acA2500-14gm works differently. For more information, see
Section 10.8 on page 266.
Reduced Resolution
Using binning effectively reduces the resolution of the camera’s imaging sensor. For example, the
sensor in the acA640-100gm camera normally has a resolution of 659 (H) x 494 (V). If you set this
camera to use horizontal binning by 3 and vertical binning by 3, the effective resolution of the sensor
is reduced to 219 (H) by 164 (V). (Note that neither dimension of the sensor was evenly divisible by
3, so we rounded down to the nearest whole number.)
Possible Image Distortion
Objects will only appear undistorted in the image, if the numbers of binned lines and columns are
equal. With all other combinations, the imaged objects will appear distorted. If, for example, vertical
binning by 2 is combined with horizontal binning by 4 the widths of the imaged objects will appear
shrunk by a factor of 2 compared to the heights.
If you want to preserve the aspect ratios of imaged objects when using binning, you must use
vertical and horizontal binning where equal numbers of lines and columns are binned, e.g. vertical
binning by 3 combined with horizontal binning by 3.
Binning’s Effect on AOI Settings
When you have the camera set to use binning, keep in mind that the settings for your area of interest
(AOI) will refer to the binned lines and columns in the sensor and not to the physical lines in the
sensor as they normally would. Another way to think of this is by using the concept of a "virtual
sensor." For example, assume that you are using an acA640-100gm camera set for 3 by 3 binning
as described above. In this case, you would act as if you were actually working with a 219 column
by 164 line sensor when setting your AOI parameters. The maximum AOI width would be 219 and
the maximum AOI height would be 164. When you set the X Offset and the Width for the AOI, you
will be setting these values in terms of virtual sensor columns. And when you set the Y Offset and
the Height for the AOI, you will be setting these values in terms of virtual sensor lines.
For more information about the area of interest (AOI) feature, see Section 10.5 on page 225.