Telephoto Lens Calibration at 300 mm Vitaliy Orekhov

Telephoto Lens Calibration at 300 mm Vitaliy Orekhov Imaging, Robotics, & Intelligent Systems Laboratory The University of Tennessee Fall 2006 Slide

Lens Specifications • Tamron SP AF 28 -300 mm – – Ashperical Lens Elements 13 groups and 15 elements Angle of view 75 -8 deg. Focal length 28 -300 mm (11 X) – Distortion • Some barrel distortion at 28 mm • Very slight pin-cushion distortion at 300 mm • Good performance for a wider range zoom lens • http: //www. photo. net/equipment/tamron/28_300_Di/page 3. html 300 mm/5 m 3/4/2021 Slide 2/23

Nikon D 70 CCD Specifications • Modified version of the Sony ICX 413 AQ • Size: 0. 93 x 0. 61” (23. 7 x 15. 6 mm) • Pixel size: 7. 8 microns Source: Thomas Hogan’s Complete Guide to the Nikon D 70 3/4/2021 Slide 3/23

Calibration Measurements Calibration Error for Tamron 28 -300 mm Lens at 300 mm with Focus Distance of 5 m Aperture f 6. 3 f 40 Previous Results MSE 0. 631 0. 384 0. 3631 Pixel Error [x-dir. , y-dir. ] [0. 52, 0. 50] [0. 40, 0. 41] [0. 47, 0. 31] Pixel Error (Open. CV) [x-dir. , y-dir. ] [0. 61, 0. 68] [0. 69, 0. 66] [2. 0, 0. 39] Focal Length Measurement Results Using IRIS Implementation at 300 mm Aperture f 6. 3 f 40 Previous Results Measured Focal Length [mm] 277 276 234 3/4/2021 Slide 4/23 Calibration Error for Other Lenses Effective Focal Length (mm) MSE Wide Angle 0. 9520 Full Frame Fisheye 0. 6639 Fisheye 0. 9405

Calibration Results • Principal point estimation (1 -f 6. 3, 2 -f 40, 3 -previous results, x-image center) 3/4/2021 Slide 5/23 Expect some principal point shift due to misalignment of the optical components found in the lens. The position and orientation of the lens components are changed by adjusting the focus and zoom.