TY - GEN
T1 - Measurement of the modulation transfer function (MTF) of a camera lens
AU - Vernier, Aline
AU - Perrin, Baptiste
AU - Avignon, Thierry
AU - Augereau, Jean
AU - Jacubowiez, Lionel
N1 - Publisher Copyright:
© COPYRIGHT SPIE.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - An accurate characterization of optical elements is one of the pivotal skills to be learnt in the context of undergraduate optics lab work or that of continuing education. We will show an experimental apparatus designed to measure the Modulation Transfer Function (MTF) of a camera lens. The educational scope of this apparatus ranges from the study of the aberrations of the lens and its suitability for use with a given sensor, to the design of the test bench itself. A first, purely visual observation allows the trainees to single-out the aberrations exhibited by an objective. The presence of the spherical and chromatic aberrations on the axis of the objective is thus identified, and a first estimate of the cut-off frequency of this objective can be given. There, the importance of the geometrical extent of the source and the impact of the optical elements of the test bench on the measurement can also be assessed. The second part of the experiment makes use of a CMOS camera to measure the Linear Spread Function (LSF) of the camera lens and the MTF is then retrieved by Fourier transform. The experimental setup consists of a fine slit as a source, a collimator, the studied objective exhibiting conspicuous aberrations and a microscope objective to re-image the LSF either for direct observation with an eye-piece or for analysis with the camera. The latter is performed with a home-developed Matlab software.
AB - An accurate characterization of optical elements is one of the pivotal skills to be learnt in the context of undergraduate optics lab work or that of continuing education. We will show an experimental apparatus designed to measure the Modulation Transfer Function (MTF) of a camera lens. The educational scope of this apparatus ranges from the study of the aberrations of the lens and its suitability for use with a given sensor, to the design of the test bench itself. A first, purely visual observation allows the trainees to single-out the aberrations exhibited by an objective. The presence of the spherical and chromatic aberrations on the axis of the objective is thus identified, and a first estimate of the cut-off frequency of this objective can be given. There, the importance of the geometrical extent of the source and the impact of the optical elements of the test bench on the measurement can also be assessed. The second part of the experiment makes use of a CMOS camera to measure the Linear Spread Function (LSF) of the camera lens and the MTF is then retrieved by Fourier transform. The experimental setup consists of a fine slit as a source, a collimator, the studied objective exhibiting conspicuous aberrations and a microscope objective to re-image the LSF either for direct observation with an eye-piece or for analysis with the camera. The latter is performed with a home-developed Matlab software.
KW - Line Spread Function
KW - Modulation Transfer Function
KW - characterization of optical elements
KW - cut-off frequency and sampling frequency
KW - optical test bench for aberration measurements
UR - https://www.scopus.com/pages/publications/84963623549
U2 - 10.1117/12.2223114
DO - 10.1117/12.2223114
M3 - Conference contribution
AN - SCOPUS:84963623549
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Education and Training in Optics and Photonics
A2 - Cormier, Eric
A2 - Sarger, Laurent
PB - SPIE
T2 - Education and Training in Optics and Photonics, ETOP 2015
Y2 - 29 June 2015 through 2 July 2015
ER -