Abstract: A method and apparatus for determining an axial relationship by viewing a target with an image inverter and determining the relationship of the optical axis of the image inverter relative to the position of the target by comparing the inverted view against another view. The image inverter can act as level by comparing the inverted image with a direct view of the target, or can measure an angle defined by the first target, the image inverter and a second target offset along a second axis. A mirror associated with the image inverter can provide a reflection of the second target along the reflective axis of the mirror, thus providing a measurement of the angle defined by the intersection of the reflective axis and the optical axis. Each target can comprise a bar, which can divide two contrasting portions to clarify the comparison of the inverted image and the direct or reflected image. The bar can be oriented horizontally or vertically, or at any appropriate orientation to support survey of angles or lines.