An IQeye camera has an automatic shutter, that will auto adjust to get a proper exposure.
The shutter speed has a range of 30Hz to 8000Hz (1/7 sec to 1/8000 sec)
When Lightgrabber™ is used, the shutterspeed can even go as low as 15 Hz or 7Hz (Lightgrabber™ x 2 or x 4)
The lower the light level in the scene, the slower the shutter is.
In a really dark scene, the shutter speed can go as low as 7Hz (with Lightgrabber™ x 4)
With a slow shutter speed, you get a nice bright picture in a low light scenario.
However, if there are (fast) moving objects in the scene, you may see so called ‘motion blur’
The moving object looks fuzzy and unfocused, while the static surrounding is still sharp.
This makes is hard to recognize faces or read license plates.
There are several thing you can do to avoid this motion blur:
- Make sure the iris (aperture) of the lens is all the way open.
This will let the maximum amount of light in the camera, allowing the camera to maintain a higher shutter speed.
- Make sure there is sufficient light in the scene.
More light will allow the camera to maintain a higher shutter speed. - Disable Lightgrabber™
Lightgrabber™ will cause the shutter speed to go as low as 15Hz or 7Hz.
This is great for static scenes, but may be too slow for scenes with moving objects or people.
- You can limit the cameras minimum shutter speed as follows:
http://x.x.x.x/set.oid?OidTB1.2.8.27.1=100 (Where x.x.x.x is your cameras IP address)
If the browser is not already logged in, it will ask for the camera log in credentials (default: user root password system)
In this example we set the camera to never use a lower shutter speed than 100Hz.
You will have to try what is the best minimum shutter speed for you.
Setting this value too high can cause the image to be too dark, when the camera has reached it maximum gain level.
Note 1:
IR illuminations is often used, when the camera needs to be able to read license plates.
As cars can move very fast thru the scene, a relatively high shutter speed can be selected (i.e. 300 Hz)
The image will be dark, but the retro-reflective paint on the license plates will light up brightly in a dark scene.
The IR light will mainly reflect by the retro-reflective paint, in the direction where the light came from,
so the IR illumination needs to be positioned close to the camera.
Note 2:
There are several methods of setting the OID values.
- You can use the URL method as discussed above: http://x.x.x.x/set.oid?OidTB1.2.8.27.1=100
- You can also telnet into the camera and use the command: oid set 1.2.8.27.1 100
- There are also utilities such as IQmanager that allow you to set OID values.
Note 3:
In the current generation of cameras, you can show the current shutterspeed in the image.
The current gain can be made visible in the image by using $IMGDBG in the ‘overlay text’ in the Setup > Basic tab.
The previous generation of cameras (i.e. IQ75x cameras etc) cannot work with the $IMGDBG image overlay.
For these cameras you can use a text overlay $O(1.2.8.7)/$O(1.2.8.24) for similar functionality
This will show gain/shutterspeed values in the image.
Contact the IQeye support team for questions: support@iqeye.com
There is a tool called IQexposure that lets you easily adjust minimum and maximum shutter speeds, as well as other exposure parameters:
It can be downloaded here:
https://www.dropbox.com/s/oj1ma5o9wy9vxto/IQexposure1.7-Installer.zip?dl=0