# Unit Conversions

When using the 3D-L4000, you need to convert some units while working with multiple 2D/3D tools. The values you enter a 2D tool must be in pixels and in the correct coordinate system.

Example:

1. 3D Tool:

- Input: Real world units (right-handed coordinate system)

- Output: Real world units

2. 2D Tool:

- Input: Pixels (left-handed coordinate system)

- Output: Real world units

Note: This conversion is applicable only on specific 2D outputs, like the gray scale (intensity) image.

Moving from a 2D tool to a 3D one does not require any conversions. You need to go through this procedure only when using two 2D tools subsequently, or switching from 3D to 2D. The exact steps are described in the following subsections: