> For the complete documentation index, see [llms.txt](https://docs.phoenixlidar.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.phoenixlidar.com/spatialexplorer-8-and-9/user-interface/toolbars/workflow/camera-snap/auto-detect-with-manual-review.md).

# Auto-detect with manual review

When using CameraSnap in the **Auto-detect with review** mode, **CameraSnap** finds matching features (generally referred to as keypoints), then displays these feature matches in the **CameraSnap** **Match Explorer**:

<figure><img src="/files/vn6WoCyn186QfAdeuVTX" alt=""><figcaption></figcaption></figure>

This allows the user to remove or add matches.  Matches shown in the table are a feature match between two images. The image numbers and receptor numbers associated with the match are displayed in the leftmost columns of the table. To manually add a match, so the [Manually-Created mode](/spatialexplorer-8-and-9/user-interface/toolbars/workflow/camera-snap/manually-created-matches.md) (the process is the same).

**Approach Distance** is one of the most useful fields in the Match Explorer. Approach Distance is calculated by projecting a ray from each image to the keypoint (or feature), and computing the difference in position of the rays. Generally, the smaller approach distance, the better the match.&#x20;

{% hint style="info" %}
You can sort the matches by clicking on the column headers. A quick and easy way to filter out bad matches is to sort by **Approach Distance**, then select and remove all matches with an approach distance greater than approximately **0.10 m**.&#x20;
{% endhint %}

Try to retain at least 20 matches, however ideally you have much more. Once you have filtered the matches, you can click **Calibrate** and CameraSnap will proceed with Calibration using the available feature matches. Review the [CameraSnap report](/spatialexplorer-8-and-9/user-interface/toolbars/workflow/camera-snap/camerasnap-reports.md) to ensure a proper calibration was achieved.&#x20;