This publication demonstrates the possibility of use of free AeroSys Consulting software to calibration of digital cameras. Investigations were carried out with digital camera Canon EOS 300D. Before the elements of internal orientation of camera were determined, the stability of CMOS matrix registration of images was checked out. Appropriate pictures were taken to measure coordinates of checkpoints by AutoCAD 2000. Parameters of camera calibration were determined with the modules Direct Linear Transformation and Camera Calibration program AeroSys.