Obituary: Prof. Dr.-Ing. Schmidt-Clausen passed away.

Death notice


Prof. Dr.-Ing. Hans Joachim Schmidt-Clausen passed away on February 23, 2023 at the age of 87 in Lippstadt.

He was born in Peru in 1935, studied in Darmstadt and received his doctorate in 1968 from the Lighting Lab of the Institute of Electrotechnics at the Technical University of Darmstadt. His dissertation was about the perception of light pulses, supervised by Prof. Paul Jainski. After shorter periods of work at the Botanical Institute of Darmstadt University and at Philips Eindhoven, he moved to his main job at Hella in Lippstadt until he was appointed professor at the Technical University of Darmstadt in 1981.

His research focus was on the basic spectral sensitivity V(λ) of the human eye, supplemented by aspects of vehicle lighting and the improvement of road lighting infrastructure. Experimental research was conducted for the German Federal Highway and Street Research Institute (BASt), among others. Prof. Schmidt-Clausen was active for decades in national and international organizations for the development of regulations and rules in the field of lighting, such as the GTB and the GRE. He influenced many current legal regulations in the field of lighting.

In a visionary approach, Prof. Schmidt-Clausen founded the international vehicle lighting symposium PAL (Progress in Automobile Lighting) in 1995, which has grown into the International Symposium on Automotive Lighting (ISAL), the most-visited conference on the subject worldwide.

Professor Schmidt-Clausen officially retired at the end of 2002. Since his retirement, he has been working as an honorary professor at Fudan University in Shanghai. Prof. Schmidt-Clausen was awarded the “Golden Diesel Ring” in 2005 for his great contribution to the increase of traffic safety. He also earned great merit in the Asia Link program between the Technical University of Darmstadt, the University of Helsinki, and Fudan University in Shanghai. Prof. Khanh followed as the leader of the department for Adaptive Lighting Systems and Visual Processing from 2006 onwards.

The international lighting community bids farewell with sadness and great respect.

Prof. Schmidt-Clausen was the supervisor of the following PhD students:

  • 1984 Klaus Petry – Minimum Illumination at Daylight Work Areas
  • 1991 Jörg Ed. Hartge – Spectral Sensitivity with small Lightsources
  • 1994 Horst Finsterer – Pattern Conspicuity and perception in mesopic status
  • 1994 Helmut Frank – Traffic Sign Requirements at Night
  • 1995 Martin Enders – Comparison of Methods to determine Human Eye spectral sensitivity
  • 1995 Joachim Damasky – Lighting Requirements on Headlights
  • 1996 Herbert Wambsganss – Visibility and Requirements on Road Markings
  • 1997 Michael Hamm – Spectral Sensitivity and Visual Response Time
  • 1997 Hans-Hubert – Meseberg Lighting Reqirements on Vertical Traffic Control Systems
  • 1998 Christian Boehlau – Expert System for Layout of Vehicle Lights
  • 1998 Johannes Aulbach – Reqirements on Visual Information of Guidance Signs
  • 1999 Wolfgang Huhn – Requirements on Adaptive Light Distribution
  • 1999 Ernst-Olaf Rosenhahn – Lighting Requirements in Adverse Weather
  • 2001 Joachim Ripperger – Lighting Requirements on Rear and Stop Lamps
  • 2001 Thomas Dahlem – Methods to Evaluate Vehicle Headlights
  • 2001 Stefan Milch – Video based Detecting on-board a vehicle
  • 2001 Peter Lehnert – Vehicle Dynamics effects on Light Distribution
  • 2001 Daniel Armbruster – Adaptive Vehicle Signal Lights
  • 2003 Martin Grimm – Ambient Interior Lighting
  • 2004 Carsten Diem – Viewing Behaviour in Dynamic Traffic
  • 2005 Yandan Lin – Visual Performance Model under Mesopic Light Levels