Lichti, Derek DTredoux, WynandMaalek, RezaHelmholz, PetraRadovanovic, Robert2022-02-032022-02-032021-12-01Lichti, D. D., Tredoux, W., Maalek, R., Helmholz, P., and Radovanovic, R. (2021). Modelling extreme wide-angle lens cameras. Photogrammetric Record, 36(176), 360-380. https://doi.org/10.1111/phor.123890031-868X1477-9730http://hdl.handle.net/1880/11437710.11575/PRISM/46010The use of consumer cameras fitted with extreme wide angle (EWA) lenses for photogrammetric measurement is increasing. Conventional modelling of EWA systems relies on the pinhole camera model and up to five radial lens distortion terms. Aiming to reduce model complexity, this paper reports an investigation into an alternate approach using fisheye lens models for EWA systems, despite them not falling strictly into to the fisheye category. Four fisheye models were tested on four different cameras under laboratory conditions. The self-calibration results show superior model fit for all fisheye models over the pinhole plus radial model in terms of residual RMS. The number radial distortion of terms required for the fisheye models was lower in all cases, so model complexity was reduced. Independent assessment revealed very similar 3D reconstruction accuracy for all models. The results suggest that fisheye modelling is an advantageous alternative for EWA lens systems.engUnless otherwise indicated, this material is protected by copyright and has been made available with authorization from the copyright owner. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Camera calibrationExtreme wide-angle lensesFisheye lensesRadial lens distortionBarrel distortionjournal articleCRDPJ 505367-16 and RGPIN/03775-2018https://doi.org/10.1111/phor.12389