The photography approach is similar to both Single or Multi-sheet Calibrations. The term “target pattern” applies to the pattern of targets on the single sheet calibration grid (i.e. 4 coded targets, and a grid of dots), and the RAD Coded Targets on a series of sheets.
A little planning of the calibration photography will make the task much easier and give you better results. If you are using a paper form of the grid (or target sheets), placing and affixing with tape on the floor is probably the easiest. It is easy to take photographs from above with a tripod.
Important Note 1: Be sure to affix the grid or target sheets to the floor or smooth surface so that the targets don’t move between shots. Even the slightest movement during the taking of photos can throw the calibration off and degrade its quality, sometimes substantially. Also, affix the grid or sheets and move around it when taking photos, i.e. do not fix the camera position and rotate the target pattern. If your camera cannot move contact PhotoModeler Technologies support for advice.
Important Note 2: Three settings on your camera should be disabled if they are present: 1) Image Stabilization (or ‘shake reduction’) must be off.; 2) Auto-rotation (detects portrait vs landscape) must be off; 3) It is recommended to lower the camera’s ‘sharpening’ setting (i.e.. make images less sharp).