Knowledge Base

Procedure (General)

1. Make sure EthoVision XT (and Media Recorder, when present on the computer) are not running.
2. Start the Basler Pylon Viewer software that comes with the camera.

   Note: The Basler Pylon Viewer software is installed automatically when you install the camera drivers.

3. Choose Tools > Options and check that the User level is set to Expert or Guru.
4. In the Devices panel, double-click the item Basler under GigE or USB depending on the camera you have.
5. To preview the camera image, click the Continuous Shot button on the toolbar.

   Important: Do not use the Record button if you want to record video. This creates very large files. Always use EthoVision XT.

6. Under Features, open the Basler GigE camera chosen in Step 4 and choose the settings you would like to change. Follow the instructions below that apply.

   Note: To be able to adjust the settings, click the Stop button first.

7. Save the settings. See Item 7 below.

Camera Gain

This applies to both color and black/white Basler cameras. Increasing the gain will brighten the image.

Important: Increasing gain also increases image noise. Do this only if no other option is left to improve the image brightness. For example, make sure that the lens aperture is maximal, and increase lighting.

1. In the Features panel, click Analog Control.
2. From the Gain Auto list, select Off.
3. Next to Gain (Raw), select the value you require. A higher Gain results in a brighter image, but also more noise and a grainy image.
   • This value is typically low, often no higher than 2. Use Exposure to brighten up the image more if needed.
4. Save the settings. See Item 7 below.

Pixel Format

1. Under Image Format Controls, select Pixel Format. Select the one you require via the drop-down list.
   • Select Mono8 for black and white (monochrome) cameras.
   • Select Bayer RG 8 for color cameras.
2. Save the settings. See Item 7 below.

How To Tell Which Camera You Have

Look at the model number on your camera. It will look something like this: acA1300-60xx

• Where xx = gm, this camera is black and white (monochrome).
• Where xx = gmNIR, this is a black and white (monochrome) camera with Near Infrared.
• Where xx = gc, this is a color camera.
• Note that all DanioVision units come with a black and white (monochrome) camera.

Center Camera

With this procedure you make sure the camera view is centered.

Important: If you center the camera view in EthoVision XT, the settings are not stored in the camera drivers. In Pylon Viewer you make sure that the settings are stored in the drivers, also for future experiments.

1. In the Features panel, open the Basler camera item and then the AOI Controls item.
2. Select both options Center X and Center Y.
3. Save the settings. See Item 7 below.

Note: If you bought your GigE camera elsewhere or from Noldus but did not buy a PC at the same time, please set:

• Width to 1280
• Height to 960

If you cannot edit Width & Height (grayed out), stop the live feed by clicking the Stop button.

White Balance

If you have a color camera, you also need to adjust its white balance.

1. Click Color Improvements Control.
2. Point the camera at a piece of white paper so that the camera image is entirely white. Click in the field next to Balance White Auto and select Once from the list.
3. Save the settings. See Item 7 below.

Camera Exposure Time

The exposure time (or shutter time) is the time the camera shutter is kept open to let light in. The exposure time limits the maximum achievable frame rate. If the sum of the exposure time and the time needed for reading the chip (readout time) is greater than the time between consecutive video frames, the next frame may be dropped, resulting in a lower frame rate and missed samples during tracking.

You will apply the following settings via Acquisition Control:

• Exposure Mode
• Exposure Auto
• Acquisition Frame Rate (Abs) [Hz]
• Exposure Time (Abs) [us]

Procedure

To adjust camera exposure until it matches the frame rate, follow these steps:

1. In the Features panel, open the Basler camera item and then double-click Acquisition Controls.
2. Set the Exposure Mode to Timed.
3. Set Exposure Auto to Off.
4. Set Acquisition Frame Rate (Abs) [Hz] to 25 or 30.
5. Set Exposure Time (Abs) [us] by entering the exposure time you require, in microseconds. Press Tab or click another field to confirm.
   • This value will vary between 2000 and 15000 depending on your lighting needs and your Gain setting.
   • For Zebrafish larvae, enter 4000 or 2000, depending on the video resolution chosen.
   • In all other cases, you may choose a higher value. Faster animals require shorter exposure times.
6. To check that the exposure time is compatible with the frame rate you have chosen, click the Continuous Shot button on the toolbar.

DanioVision GigE Camera Exposure Guidelines

• If resolution in EthoVision is 1280 x 960, use an exposure time of 4000.
• If resolution in EthoVision is 640 x 480, use an exposure time of 2000.
• Use the highest resolution that allows all wells to be seen onscreen in EthoVision.

General Exposure Recommendations

• The ideal range of exposure will likely be anywhere from 2000 to 10000.
• If lighting in the room is low, you will likely need a higher exposure (try 8000 up to as high as 15000).
• It is unlikely you will need anything above 20000, as motion blur in rodents has been observed at this level.
• When tracking in IR with an NIR GigE camera, you may need an exposure setting around 30000 in order to brighten the image enough for tracking in EthoVision.
• A higher exposure setting will result in a brighter image, while a lower exposure setting will result in a darker image. However, too-high exposure will result in dropped frames, and too-low exposure may result in an image that flickers or changes rapidly between light and dark.
• The brightness of the image will also be affected by the aperture setting on the lens and by the camera gain. When adjusting the camera lens, the aperture adjustment will be labeled Open-Close or O-C. Turning it towards Open will brighten the image, while Close will darken the image.

At the bottom of the live video window, locate the frame rate resulting from the new exposure time. This should match the value set for Acquisition Frame Rate (Abs) [Hz]. Noldus recommends 25 or 30.

If the resulting frame rate is lower than Acquisition Frame Rate (Abs) [Hz], then either lower the exposure time (this will make the video image darker; open the lens diaphragm to compensate), or lower the video resolution. Repeat until you see the expected frame rate.

7. Save the settings. See Item 7 below.

Source: EthoVision XT 18 - GigE Install and Setup, Noldus Information Technology