---
title: "Adjust the focus and aperture"
canonical: "https://help.vicon.com/space/ShogunMarkerless121/1253507125/Adjust%20the%20focus%20and%20aperture"
format: markdown
---
While you are positioning the cameras and checking that they give coverage of the whole volume (see [Check the coverage of the capture volume](https://vicon-help.atlassian.net/wiki/spaces/ShogunMarkerless121/pages/1253507169)), to achieve a good marker image you may need to adjust the camera lens.

## Adjust focus and aperture for markerless cameras

Begin by ensuring the aperture is correctly adjusted for the Vanguard cameras in your system.

**Vicon Vanguard:**


> ![Vicon Vanguard camera lens with aperture control labeled.](media://e33b9005-bb65-47f3-8ccf-bfceb26109d8)

Set the aperture on the camera to enable you to view the scene.

> ✅ **Tip**  
> ✅ For a 5 m x 5 m volume, set the aperture to 1.8.

If the image that you see of the subjects isn't sharp enough, ensure the volume is sufficiently and evenly lit, and focus the camera so that you can see a clear image of the subjects throughout the volume (or within the part visible to the camera). For information on adjusting the brightness of the Vicon IR lights, see [Specify the brightness of the IR lights](https://vicon-help.atlassian.net/wiki/spaces/ShogunMarkerless121/pages/1253507160/Position+and+optimize+IR+lights#specifyBrightness).

To focus the camera, loosen the grub-screw underneath the lens and screw the entire lens in/out. 

> Macro (scroll-pagebreak)

## Adjust focus and aperture for optical cameras (optional)

If your system includes optical cameras, which are needed for tracking props, make any necessary adjustments to the focus and aperture of these cameras.

Depending on your Vicon camera model, you may find two or three adjustment rings on the lens. These control the focus and aperture, and if the camera has an additional ring, the focal length (zoom).

** Vicon Valkyrie:**    

> ![Vicon Valkyrie camera with focus, aperture and zoom controls labeled.](media://d9357861-9292-4ed2-883b-90cdbfa429a7)

**Vicon Vero:**

> ![Vicon Vero camera with focus, aperture and focal length controls labeled.](media://397fb819-7704-47db-afd4-d923e7df3482)

> Macro (scroll-pagebreak)

**Vicon Viper:**

> ![Vicon Viper camera with aperture control labeled.](media://e33b9005-bb65-47f3-8ccf-bfceb26109d8)

**To focus an optical camera:**

1. To make focusing easier, in the **View Filters**, go to the **2D Data** options and select **Maximize Grayscale**, which zooms the view into any visible markers.
2. Fully open the **Aperture** ring.
3. Adjust the **Focus** ring so that the markers become round and clear. As you rotate the focus ring, notice the marker images get smaller and then at some point will begin to get larger again. Good focus is when the marker is at its smallest size. Leaving this setting at infinity **∞** is normally suitable. Aim for a marker image similar to the following:
4. Close the **Aperture** ring so that as much background noise as possible is removed without compromising the quality of the marker image. Try to obtain good, clear images of markers even when they are close together, as shown in the following image, where the markers on the left are touching. The markers should not be too small, and the center should be just off-white (not fully saturated) when viewed from the middle of the volume.