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Minutes of the meeting

Date:

June 11, 2004

Time:

10:50 a.m. 12:30 p.m.

Place:

AIST, Tokyo Waterfront, Japan

Present:

Liisa Halonen
Marjukka Eloholma
Ken Sagawa
Nana Itoh
Miyoshi Ayama
Francoise Viénot
János Schanda
Peter Bodrogi
ChangSoon Kim
Sharon McFadden
Osvaldo da Pos
Mike Pointer
Yasuhisa Nakano
Hirohisa Yaguchi
Günther Heidel

Finland
Finland
Japan
Japan
Japan
France
Hungary
Hungary
Korea
Canada
Italy
UK
Japan
Japan
Germany
(chairman)











(observer)
(observer)
(observer)

 

1. Opening of the meeting

Liisa Halonen opened the meeting.

2. Approval of the Agenda

The Agenda was approved.

3. Election of secretary for the TC and noting TC members

Liisa Halonen suggested, that Marjukka Eloholma would become the secretary of the TC1-58. This was approved.

A list of the current TC members was viewed, the current members are: Halonen FIN, da Pos IT, Derefeldt SE, Leetzow US, Lewin US, Sagawa JP, Viénot FR, Yandek GB. A list was passed around, where the attendants were asked to mark whether they are or want to become members, or whether they are observers in the meeting (Attachment 1: Updated list of TC1-58 members - doc file).

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4. Presentation of mesopic research work

There were four presentations of current or recent research work done in the mesopic field.

Marjukka Eloholma presented a European collaboration project MOVE ‘Mesopic Optimisation of Visual Efficiency’, which is underway and which will develop new mesopic spectral sensitivity functions using a performance based approach (slides in Attachment 2 - pdf file).

Mike Pointer gave a presentation of empirical models for visual performance at mesopic light levels, which is based on a UK consortium’s research work (slides in Attachment 3).
Francoise Viénot gave a presentation of heterochromatic photometry in the mesopic domain (slides in Attachment 4).

Yasuhisa Nakano gave a presentation of the concept of equivalent luminance (slides in Attachment 5).

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5. Terms of reference

The chairman informed, that the TC1-58 was established in 2000. So far there have not been any actual activities in the TC work. The intention is now to start the TC work effectively.

The terms of reference were discussed. The original terms of reference are:

‘To define visual performance and related terms. To investigate performance based photometry and colorimetry in the low photopic to scotopic region. To investigate and establish a relationship between performance and equivalent luminance’.

The chairman expressed, that there is need to change the terms of reference, as the present terms of reference are too broad to be reached and that she intends to complete the TC in four years. Each sentence of the terms of reference where then separately discussed.

The chairman presented, that in her opinion to fulfil the first sentence of the terms of reference (To define visual performance and related terms), there are four different subtasks that should be completed. These are: define most relevant mesopic applications, define most critical visual tasks in each application, define related terms and get a definition of mesopic visual performance.

Concerning the second sentence of the terms of reference (To investigate performance based photometry and colorimetry in the low photopic to scotopic region), the chairman proposed, that the word ‘colorimetry’ should be removed, as it would make the work of the TC too broad. This was approved. The chairman presented, that the investigation of performance based mesopic photometry should include two items: collect and analyse the existing and new mesopic models based on visual performance, generate new data for performance based mesopic models.

Concerning the third sentence of the terms of reference (To investigate and establish a relationship between performance and equivalent luminance), the chairman expressed that the idea of this sentence was originally to see how different the performance based systems are to the brightness based systems based on equivalent luminance. She said, that recent work shows that they will be completely different, which was also a conclusion made in the CIE Div1&2 joint meeting in Tokyo on June 9, 2004. Therefore she expressed, that there is little value to this part of the original terms of reference and that it should be removed.

After discussion of the terms of reference, the meeting came up to a proposal for new terms of reference as follows:

To define mesopic visual performance and related terms. To investigate performance based photometry in the luminance region below approximately 10 cd/m2. To propose a model for the basis of performance based mesopic photometry.

This proposal was handed to the Div 1 Director Sharon McFadden in the meeting.

Due to limited time, there was no time for items 6 and 7. At this point the chairman closed the meeting and thanked everyone for a good meeting and discussions.

The members will receive a proposal for TC work programme from the chairman after the meeting.

Approval of the new terms of reference:

The Div 1 approved the new terms of reference in a follow-up Div 1 meeting after the TC meeting on June 11, 2004. The new terms of reference of TC1-58 are:

‘To define mesopic visual performance and related terms. To investigate performance based photometry in the luminance region below approximately 10 cd/m2. To propose a model for the basis of performance based mesopic photometry.’

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