Traditional zoom lens designs employ multiple moving lens elements to provide simultaneous control of focal length and
focal plane. We present an example of a simplified and compact zoom lens design by employing a single moving
element to control only the focal length. In this zoom lens, wavefront coding is used to control the defocus. We describe
the principles of operation with special attention to image processing. We simulate imaging and image restoration
capabilities and present that the zoom lens provides high imaging quality.
The design of modern imaging systems is intricately concerned with the control of optical aberrations in systems that can
be manufactured at acceptable cost and with acceptable manufacturing tolerances. Traditionally this involves a multi-parameter
optimisation of the lens optics to achieve acceptable image quality at the detector. There is increasing interest
in a more generalised approach whereby digital image processing is incorporated into the design process and the
performance metric to be optimised is quality of the image at the output of the image processor. This introduces the
possibility of manipulating the optical transfer function of the optics such that the overall sensitivity of the imaging
system to optical aberrations is reduced. Although these hybrid optical/digital techniques, sometimes referred as
wavefront coding, have on occasion been presented as a panacea, it is more realistic to consider them as an additional
parameter in the optimisation process. We will discuss the trade-offs involved in the application of wavefront coding to
low-cost imaging systems for use in the thermal infrared and visible imaging systems, showing how very useful
performance enhancements can be achieved in practical systems.
Traditional zoom lens designs employ multiple moving lens elements to provide simultaneous control of focal length and
focal plane. We present an approach to a design of a simplified zoom lens by employing a single moving element to
control only the focal length. We show that the defocus in miniaturized zoom lenses with a single moving element can be
corrected by the use of wavefront coding, although this introduces a modest reduction in signal-noise-ratio. As an
example, we present a design of a miniaturized 10 mm long wavefront coded 2.3x optical zoom lens with a single
moving lens element.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.