# Camera position and settings

tip Watch the video Set Up the Cameras, in the EthoVision XT video tutorial (Help > Video Tutorial).

Attach the cameras

With the ceiling mount

With the Autopole

For this configuration you need an Autopole, a SuperClamp and a camera adapter (all shown in the following figure).

The Autopole range is 2.1-3.7m, or up to 5.7m with the extension (sold separately).

note The elements shown here may slightly differ from those you have purchased.

How to attach the camera to the SuperClamp:

1.Connect the camera to the SuperClamp through the brass stud connector or the camera adapter.

2.The Autopole gets clamped between the jaws of the SuperClamp. Turn the handle to tighten the SuperClamp to the Autopole.

Horizontal installation is mainly for top view tracking. For this you need the Autopole and the SuperClamp.

Vertical installation is for top view tracking and side view tracking. For this you need the Autopole, the SuperClamp and a camera adapter (see above). For more flexibility you can use a variable friction arm attached between the SuperClamp and the camera adapter.

Suspended ceilings

If you need to attach the camera to suspended ceilings, you can get a special mount that has two parts which move like scissors. Move them to open up the mount and it will fit over the framework of the suspended ceiling, then close them to hold. Attach the camera adapter and then the camera.

This is a temporary mount, it is sturdy enough but you can always open the mount to remove it from the ceiling and place it elsewhere. If you have a suspended ceiling it’s probably the best solution.

Cable length

The maximal length of the cable between camera and computer depends on the type of camera you use.

▪For GigE cameras and Analog cameras: 100 m.

▪For USB 3.0 cameras: 5 m. You can increase this length by means of an active extension cable (not tested though). See Connect the USB 3.0 camera to the PC.

Things to check

▪Position the camera perpendicular to the plane in which the animal moves. If this is not the case, the shape of the arena and subject inside will appear distorted on the screen and calculated distances, velocities and spatial statistics will be incorrect.

▪Anchor the entire setup. Secure the position of the arena, camera and illumination relative to each other, and fasten the camera zoom, focus control and aperture settings.

▪Adjust the zoom setting (or select the appropriate lens) and focus the lens until the entire experimental arena is visible on the screen and is displayed in focus.

▪When using multiple cameras, pay attention to the zoom settings. These should be in such a way that the apparent size of the arenas is the same since you calibrate the distance for all the cameras (Shared calibration). If that is not possible, make one calibration for each arena (Unshared calibration). See Calibrate multiple arenas

▪Turn off all automatic camera settings: focus, gain, exposure (auto-iris), anti-shake.

▪Adjust the camera aperture until the image shows maximal contrast. Depending on how bright your IR setup is, you might need to open the aperture on the lens all the way (do this first) and/or adjust the cameras Gain (Raw) and/or adjust the Exposure time in Pylon Viewer. See Configure the digital camera

See also Lighting setup

View the camera image in EthoVision XT

1. important When using digital cameras, close the camera software Basler pylon Viewer before operating the camera in EthoVision XT.

2.Create a new experiment.

3.Choose Setup > Experiment Settings.

4.Set the Video source to Live tracking. For details, see Video source.

5.Click the camera button (for single cameras) or the eye button (for multiple cameras in merged view).

Image magnification

If you need to get higher magnification images than is available with a standard lens (get 'closer'), then you can use one of the following techniques.

Macro lens

A true macro lens, that is, a lens of a magnification of at least 1:1 (expressed as 'real world': CCD chip size) usually gives good quality images. However, it is often expensive and probably gives a lower magnification than either a close-up filter or an extension ring.

Extension rings

An extension ring inserted between the camera body and the lens enables you to focus on subjects closer to the camera, and so provides a greater magnification. An extension ring is usually cheaper than a true macro lens, but more expensive than a close-up filter. It may give a reduction in optical quality, and it will reduce the light intensity of the signal, but you can use it to get very high magnifications.

Close-up filter

This is a lens attached in front of the normal lens, to give greater magnification. It is also known as a close-up lens. It works by shortening the focal length of the lens while keeping the lens-to-camera distance constant, which increases the magnification of the lens. The strength of a close-up filter is measured in diopters, which is the fraction by which the lens' focal length is shortened. Thus, a +3 lens reduces the focal length of the lens to which it is attached by 1/3. A close-up filter is usually cheaper than a macro lens or extension ring, but it gives lower magnification, and poorer optical quality.

Microscope

EthoVision XT tracks well from cameras attached to microscopes. Use back-lighting to maximize contrast.

Change color to monochrome

If you If you have a color camera, you can temporarily change it to monochrome by changing the Pixel format setting. For Basler cameras:

▪In pylon Viewer, change the Pixel format to Mono8. See Set the pixel format

▪In EthoVision XT, set the Color space to Y800. See Adjust camera settings in EthoVision XT > Color space

See also Settings for the color camera