In general, the shutter speed controls the frame rate of the camera. So, if you're in a low light environment and AGC - Automatic Gain Control - is set to "Average" (the default setting), the camera's firmware will decrease the shutter speed to try and brighten up the picture, which results in a lower frame rate. The converse is also true with bright scenes, in which the firmware will increase the shutter speed, which effectively increases the frame rate.
Below, two methods are offered, with instructions respective to each driver. Note that these methods should only be used where lighting conditions remain constant (not recommended for outdoor environments.)
1. One method to increase the frame rate in a low light environment is to use the additional "Peak" and "Center" AGC options, which will look only at the lighter portions of the screen or at the center of the picture, respectively.
If you are using the DirectShow driver:
Run Watchport Viewer and click "Options / Video Capture Filter", click the Advanced tab, then select either "Peak" or "Center" for "AGC Mode".
If you are using the TWAIN/AVI driver:
Run VC3Viewer and click "Controls / Camera Control Panel", click the "More" button at the top-right, then select either "AGC Center Avg" or "AGC Peak Mode" for the "Auto Brightness Mode" dropbox.
2. If the above method is not sufficient, you can turn off AGC and adjust some of the other related sliders manually, to compensate.
If you are using the DirectShow driver:
A. Run Watchport Viewer and click "Options / Video Capture Filter", click the Advanced tab, then turn off AGC Mode.
B. Increase the Shutter Speed via the slider bar. FPS should increase as the picture darkens. After the FPS is at an acceptable level, to lighten the picture, increase Brightness, Gamma, and Backlight.
For example, try these settings: Shutter Speed = 1/32 Secs, Brightness = 100%, Gamma = 2.54, Backlight = 5%
If you are using the TWAIN/AVI driver:
A. Run VC3Viewer and click "Controls / Camera Control Panel", click the "More" button at the top-right, then select "AGC Off" for the "Auto Brightness Mode" dropbox.
B. Increase the Shutter Speed via the slider bar. FPS should increase as the picture darkens. After the FPS is at an acceptable level, to lighten the picture, increase Gamma and Backlight.
For example, try these settings: Shutter Speed = 1/32 SEC, Gamma = 2.54, Back Light Compensation = 5%
Last updated:
Jan 11, 2024