Camera setup lab Professor Fabrice Pierron University of

Camera set-up lab Professor Fabrice Pierron University of Southampton

Magnification (1/3) A image B Object Magnification f f Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 2/15

Magnification (2/3) Maximum magnification Minimum image pixel size 3. 45 / 0. 125 = 27 mm Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 3/15

Magnification (3/3) § Verification – Minimum imaging distance (450 mm) 44 pixels Object pixel size: 1000/44 = 22. 7 mm M = 3. 45/22. 7 = 0. 15 Decent approximation Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 4/15

Camera noise Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 5/15

Good contrast images Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 6/15

Low contrast image Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 7/15

Good vs low contrast images § Histograms Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 8/15

Noise § Noise is not constant with grey level: grey level images have less noise 1. 5% of dynamic range 0. 2% of dynamic range Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 9/15

Performance evaluation (1/3) § Good contrast images, subset 32, step 16, units: pixel Horizontal Mean: 0. 165 Std: 0. 022 Vertical Mean: -0. 1 Std: 0. 023 Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 10/15

Performance evaluation (2/3) § Low contrast images, subset 32, step 16, units: pixel Horizontal Mean: 0. 077 Std: 0. 022 Vertical Mean: -0. 1 Std: 0. 019 Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 11/15

Performance evaluation (3/3) § Noise as a function of subset size (50% overlap) Good contrast Low contrast Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 12/15

Out of plane displacement (1/2) § Out-of-plane displacement of 0. 5 mm, with 500 mm imaging distance Horizontal Mean: 1. 07 10 -3 Apparent strain from displacement: dz/z=-0. 5/500=-1. 10 -3 Apparent strain from DIC: -1. 07 10 -3 Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 13/15

Out of plane displacement (2/2) § Out-of-plane displacement of 0. 5 mm, with 500 mm imaging distance Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 14/15

Performance Table Prof. F. Pierron – SESG 6045 and BSSM Exp. Mech. Course, University of Southampton, March 2017 – Camera set-up lab 15/15