Journal of the Optical Society of Korea

Optical Society of Korea (한국광학회)
권호 표지
DOI QR코드

DOI QR Code

Evaluation of a Corrected Cam for an Interchangeable Lens with a Distance Window

  • Kim, Jin Woo (R&D Team, Digital Imaging Business, Samsung Electronics Co., Ltd.) ;
  • Ryu, Jae Myung (Department of Optical Engineering, Kumoh National Institute of Technology) ;
  • Jo, Jae Heung (Department of Photonics and Sensors, Hannam University) ;
  • Kim, Young-Joo (Department of Mechanical Engineering, Yonsei University)
  • Received : 2013.12.13
  • Accepted : 2014.01.17
  • Published : 2014.02.25
Download PDF
⟨ Previous Next ⟩

Abstract

Recently, the number of camera companies that produce commercializing interchangeable lens systems such as digital single lens reflex (DSLR) and compact system camera (CSC) lenses has been gradually increasing. These interchangeable lenses have various kinds of lenses with distinct specifications. In particular, the distance window among these specifications is the function most preferred by customers. Mechanical manual zoom and manual focus in these high end camera lenses with a distance window are in particular desirable specifications and are required for product quality. However, the AF lens group is linked to the zoom cam and moves. Because the AF lens group moves along with the object distance, we can not realize the distance window with only zoom locus calculation. In this paper, in order to solve the problem, we suggest an optical calculation method for a corrected AF zoom cam for an interchangeable lens with a distance window to achieve product differentiation and analyze the error in the calculation.

Keywords

References

  1. Olympus Imaging Corp., "Benefits of four thirds system," (Olympus Imaging Corp., 2012), http://www.four-thirds.org/ en/fourthirds/index.html.
  2. Canon Inc., "EF70-200mm F2.8L IS II USM," (Canon Inc., 2013), http://cweb.canon.jp/ef/lineup/tele-zoom/ef70-200 -f28l-is-ii/spec.html.
  3. Sigma Corp, "APO 70-200mm F2.8 EX DG OS HSM," (Sigma Corp, 2013), http://www.sigmaphoto.com/product/ apo-70-200mm-f28-ex-dg-os-hsm.
  4. Carl Zeiss AG, "Manual focusing with AF camera systems," (Carl Zeiss AG, 2013), http://lenses.zeiss.com/camera-lenses /en_de/website/photography/what_makes_the_difference/man ual_focusing.html.
  5. J. M. Ryu, J. H. Jo, G. M. Kang, H. J. Lee, and S. Yoneyama, "Focus adjustment method with statistical analysis for an interchangeable zoom lens with symmetric error factors," Korean J. Opt. Photon. (Hankook Kwanghak Hoeji) 22, 230-238 (2011). https://doi.org/10.3807/KJOP.2011.22.5.230
  6. Digital Photography School, "Mastering the zoom effect," (Digital Photography School, 2013), http://digital-photographyschool. com/using-the-zoom-effect.
  7. K. Tomoki, "Large-aperture telephoto zoom lens with vibrationproof function," JP2011-158599 (Japanese ed.) (2011).
  8. Y. Atsushi, "Large-aperture telephoto zoom lens with antivibration function," JP2011-099964 (Japanese ed.) (2009).
  9. M. T. Chang, "Pupil aberration in modular zoom lens design," Dissertation of Ph. D. degree, The Univ. of Arizona (1998).
  10. J. H. Oh, J. M. Ryu, and J. H. Jo, "Analytic calculation method of zoom loci of zoom lens systems with infinite object distance," Korean J. Opt. Photon. (Hankook Kwanghak Hoeji) 24, 125-134 (2013). https://doi.org/10.3807/KJOP.2013.24.3.125

Cited by

  1. Optical Design and Fabrication of a Large Telephoto Zoom Lens with Fixed f/2.8 and Light Autofocus Lens vol.19, pp.6, 2015, https://doi.org/10.3807/JOSK.2015.19.6.629
  2. Three Degrees of Freedom Global Calibration Method for Measurement Systems with Binocular Vision vol.20, pp.1, 2016, https://doi.org/10.3807/JOSK.2016.20.1.107