Evalglare - Luminance or Illuminance

radiance-general
1

Sorry for what must be obvious questions. I have just compiled
evalglare for Linux and I have run a few test images albeit the images
were very low res. I have read various papers and posts on the net and
seen the images referred to as luminance images and illuminance images.
So which is it? Part of me says luminance as brightness is more
relative to glare, on the other hand my understanding of DGP is that it
measures illuminance at the eye. Which led to me confusing myself over
the type of image required. Certainly if you try both, the results are
different, however the images I am using are crude with just 1 bounce so
that could easily explain the difference.

Also I read the luxeuropa2005.pdf on the evaluation method etc. However
I was still at a loss as to what the DGP results really meant. E.g. if
the DGP result is 0.4756 what does that mean. The document talked about
levels below 0.2 not being reliable.

The other evalglare posts were useful wrt -vth and -vta, also the
picture header. Thank you.

Regards

Andrew

···

__________________________
Andrew Bissell

B.Eng(Hons) C.Eng MSLL MCIBSE MIET
Associate Lighting Designer

Cundall Light4
Direct: 0161 200 1235
Mobile: 07899 907 978

Office: 0161 244 5660

P Please consider the environment before printing this e-mail

Cundall Johnston & Partners LLP is a limited liability partnership registered in England and Wales.Registered number OC300389.
Registered office: Horsley House, Regent Centre, Gosforth, Newcastle upon Tyne, NE3 3LU
Privilege and Confidentiality Notice: Use of this email and any attachments is subject to the terms on our Website at http://www.cundall.com/email.htm
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2

Hi Andrew,

You definitely want a luminance image -- using -i would give you wrong results. Evalglare should add up luminances with the appropriate weighting to get vertical illuminance at the eye.

Cheers,
-Greg

···

From: "Bissell, Andrew" <[email protected]>
Date: October 2, 2010 1:07:53 PM PDT

Sorry for what must be obvious questions. I have just compiled evalglare for Linux and I have run a few test images albeit the images were very low res. I have read various papers and posts on the net and seen the images referred to as luminance images and illuminance images. So which is it? Part of me says luminance as brightness is more relative to glare, on the other hand my understanding of DGP is that it measures illuminance at the eye. Which led to me confusing myself over the type of image required. Certainly if you try both, the results are different, however the images I am using are crude with just 1 bounce so that could easily explain the difference.

Also I read the luxeuropa2005.pdf on the evaluation method etc. However I was still at a loss as to what the DGP results really meant. E.g. if the DGP result is 0.4756 what does that mean. The document talked about levels below 0.2 not being reliable.

The other evalglare posts were useful wrt –vth and –vta, also the picture header. Thank you.

Regards

Andrew

3

Thanks Greg, very much appreciated.

Regards

Andrew

···

__________________________
Andrew Bissell
B.Eng(Hons) C.Eng MSLL MCIBSE MIET
Associate Lighting Designer
Cundall Light4
Direct: 0161 200 1235
Mobile: 07899 907 978
Office: 0161 244 5660
 Please consider the environment before printing this e-mail

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Greg Ward
Sent: 02 October 2010 22:12
To: Radiance general discussion
Subject: Re: [Radiance-general] Evalglare - Luminance or Illuminance

Hi Andrew,

You definitely want a luminance image -- using -i would give you wrong results. Evalglare should add up luminances with the appropriate weighting to get vertical illuminance at the eye.

Cheers,
-Greg

From: "Bissell, Andrew" <[email protected]>
Date: October 2, 2010 1:07:53 PM PDT

Sorry for what must be obvious questions. I have just compiled evalglare for Linux and I have run a few test images albeit the images were very low res. I have read various papers and posts on the net and seen the images referred to as luminance images and illuminance images. So which is it? Part of me says luminance as brightness is more relative to glare, on the other hand my understanding of DGP is that it measures illuminance at the eye. Which led to me confusing myself over the type of image required. Certainly if you try both, the results are different, however the images I am using are crude with just 1 bounce so that could easily explain the difference.

Also I read the luxeuropa2005.pdf on the evaluation method etc. However I was still at a loss as to what the DGP results really meant. E.g. if the DGP result is 0.4756 what does that mean. The document talked about levels below 0.2 not being reliable.

The other evalglare posts were useful wrt –vth and –vta, also the picture header. Thank you.

Regards

Andrew

_______________________________________________
Radiance-general mailing list
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http://www.radiance-online.org/mailman/listinfo/radiance-general

Cundall Johnston & Partners LLP is a limited liability partnership registered in England and Wales.Registered number OC300389.
Registered office: Horsley House, Regent Centre, Gosforth, Newcastle upon Tyne, NE3 3LU
Privilege and Confidentiality Notice: Use of this email and any attachments is subject to the terms on our Website at http://www.cundall.com/email.htm
If you cannot access these terms, please email [email protected] with SEND TERMS in the subject heading or telephone +44 (0191) 213 1515 and we will send you a copy.
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4

Hi Andrew,

yes, evalglare needs a 180° fish-eye(-vta)- LUMINANCE image. Internally
it calculates the vertical illuminance as Greg mentioned before.

A value of 0.4756 is a rather high value (-> 48% are disturbed by glare).

At the last building simulation conference, I suggested some "glare
classes" based on user assessments, which may help to interpret the DGP
values.
(table 5 in http://www.ibpsa.org/proceedings/BS2009/BS09_0944_951.pdf ).
Further details can be found also in my dissertation "Daylight Glare in
Offices", which will be available in some days as pdf on our web-site.

Cheers,

Jan

Greg Ward wrote:

···

Hi Andrew,

You definitely want a luminance image -- using -i would give you wrong results. Evalglare should add up luminances with the appropriate weighting to get vertical illuminance at the eye.

Cheers,
-Greg

From: "Bissell, Andrew" <[email protected]>
Date: October 2, 2010 1:07:53 PM PDT

Sorry for what must be obvious questions. I have just compiled evalglare for Linux and I have run a few test images albeit the images were very low res. I have read various papers and posts on the net and seen the images referred to as luminance images and illuminance images. So which is it? Part of me says luminance as brightness is more relative to glare, on the other hand my understanding of DGP is that it measures illuminance at the eye. Which led to me confusing myself over the type of image required. Certainly if you try both, the results are different, however the images I am using are crude with just 1 bounce so that could easily explain the difference.

Also I read the luxeuropa2005.pdf on the evaluation method etc. However I was still at a loss as to what the DGP results really meant. E.g. if the DGP result is 0.4756 what does that mean. The document talked about levels below 0.2 not being reliable.

The other evalglare posts were useful wrt –vth and –vta, also the picture header. Thank you.

Regards

Andrew

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
  
--
Dipl.-Ing. Jan Wienold
Project Manager
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings, Lighting and Daylighting
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected]
http://www.ise.fraunhofer.de

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30

5

Hi Jan,

According to your previous reply about the needed view (180° fisheye -vta) for EVALGLARE, why can't we use 120° to 140°, due to the human field of view?

Sorry if it is a redundant question. I 'm just new in the list.

Cheers,

Apiparn

Jan wrote:

Hi Andrew,

yes, evalglare needs a 180° fish-eye(-vta)- LUMINANCE image. Internally

it calculates the vertical illuminance as Greg mentioned before.

A value of 0.4756 is a rather high value (-> 48% are disturbed by glare).

At the last building simulation conference, I suggested some "glare

classes" based on user assessments, which may help to interpret the DGP

values.

(table 5 in http://www.ibpsa.org/proceedings/BS2009/BS09_0944_951.pdf ).

Further details can be found also in my dissertation "Daylight Glare in

Offices", which will be available in some days as pdf on our web-site.

Cheers,

Jan

6

Hi Apiparn,

the main thing is, that for the DGP the vertical illuminance at eye
level is needed. Evalglare calculates this value from the given image
and needs therefore the full 180°!

In case you are using a camera, which does not cover the full 180°, you
can also measure the vertical illuminance and feed this illuminance
value by using the -i option. In case you are using a non-fish-eye lens
and evalglare is blocking another view than -vta, I could send you
another version until the next release will be put online. Within the
next release, all view types will be allowed.

Cheers,

Jan

Borisuit Apiparn wrote:

···

Hi Jan,

According to your previous reply about the needed view (180° fisheye --vta) for EVALGLARE, why can't we use 120° to 140°, due to the human field of view?
Sorry if it is a redundant question. I 'm just new in the list.

Cheers,

Apiparn

Jan wrote:

Hi Andrew,

yes, evalglare needs a 180° fish-eye(-vta)- LUMINANCE image. Internally
it calculates the vertical illuminance as Greg mentioned before.

A value of 0.4756 is a rather high value (-> 48% are disturbed by glare).

At the last building simulation conference, I suggested some "glare
classes" based on user assessments, which may help to interpret the DGP
values.
(table 5 in http://www.ibpsa.org/proceedings/BS2009/BS09_0944_951.pdf ).
Further details can be found also in my dissertation "Daylight Glare in
Offices", which will be available in some days as pdf on our web-site.

Cheers,

Jan

------------------------------------------------------------------------

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
  
--
Dr.-Ing. Jan Wienold
Project Manager
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings, Lighting and Daylighting
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected]
http://www.ise.fraunhofer.de

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30

7

Hi Jan,

Thanks a lot for your quick reply.
If I use the -i option (~120° -with fisheye lens), will the vertical illuminance be much different with the image of 180° view?
Moreover , for calculating DGI or UGR by Evalglare, we don't need the full 180° ?

Cheers,
Apiparn Borisuit

EPFL ENAC ICARE LESO-PB
LE 001 (Bâtiment LE)
Station 18
CH-1015 Lausanne
Téléphone +4121 69 36265<callto:+41216936265>
Fax +4121 69 32722

···

From: [email protected] [mailto:[email protected]] On Behalf Of Jan Wienold
Sent: lundi, 11. octobre 2010 11:18
To: Radiance general discussion
Subject: Re: [Radiance-general] Evalglare - Luminance or Illuminance

Hi Apiparn,

the main thing is, that for the DGP the vertical illuminance at eye level is needed. Evalglare calculates this value from the given image and needs therefore the full 180°!

In case you are using a camera, which does not cover the full 180°, you can also measure the vertical illuminance and feed this illuminance value by using the -i option. In case you are using a non-fish-eye lens and evalglare is blocking another view than -vta, I could send you another version until the next release will be put online. Within the next release, all view types will be allowed.

Cheers,

Jan

Borisuit Apiparn wrote:
Hi Jan,

According to your previous reply about the needed view (180° fisheye -vta) for EVALGLARE, why can't we use 120° to 140°, due to the human field of view?

Sorry if it is a redundant question. I 'm just new in the list.

Cheers,

Apiparn

Jan wrote:

Hi Andrew,

yes, evalglare needs a 180° fish-eye(-vta)- LUMINANCE image. Internally

it calculates the vertical illuminance as Greg mentioned before.

A value of 0.4756 is a rather high value (-> 48% are disturbed by glare).

At the last building simulation conference, I suggested some "glare

classes" based on user assessments, which may help to interpret the DGP

values.

(table 5 in http://www.ibpsa.org/proceedings/BS2009/BS09_0944_951.pdf ).

Further details can be found also in my dissertation "Daylight Glare in

Offices", which will be available in some days as pdf on our web-site.

Cheers,

Jan

________________________________

_______________________________________________

Radiance-general mailing list

[email protected]<mailto:[email protected]>

http://www.radiance-online.org/mailman/listinfo/radiance-general

--

Dr.-Ing. Jan Wienold

Project Manager

Fraunhofer-Institut für Solare Energiesysteme

Thermal Systems and Buildings, Lighting and Daylighting

Heidenhofstr. 2, 79110 Freiburg, Germany

Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133

[email protected]<mailto:[email protected]>

In office:

Mo,Tue: 8:30-18:00

We,Thu: 8:30-16:00

Fr: 8:30-15:30

8

Hi Apiparn,

if you use the -i option, you need to measure the vertical illuminance
and you should do that as close to the lense as possible ! In that case,
evalglare will use the value provided by -i as vertical illuminance.

if you don't use the -i option and provide an image smaller than 180°,
then the vertical illuminance will be less than the real value and this
might have an significant influence, depending on the situation!

The detection of the glare sources and the calculation of the
contribution of the glare sources to the DGP are only influenced minor
when you use a smaller view angle than 180°.

In case of DGI and UGR you don't need a 180° image. Be careful when
trying to evaluate these glare metrics - especially that the parameters
for the detection of the glare sources fit to your scenes and that this
fits also to the validity ranges of the equations! (e.g. DGI is only
defined for a window as glare source and the UGR is valid only for
medium sized solid angles of the artifical glare source). Always check
by using -c option, if the "correct" glare sources are detected, when
using other glare metric than DGP! The DGP is very robust concerning the
detection parameters since the main contribution comes from the vertical
eye illuminance (except you have the sun or a specular reflection of it
in the field of view).

Cheers,

Jan

Borisuit Apiparn wrote:

···

Hi Jan,

Thanks a lot for your quick reply.

If I use the --i option (~120° -with fisheye lens), will the vertical
illuminance be much different with the image of 180° view?

Moreover , for calculating DGI or UGR by Evalglare, we don't need the
full 180° ?

Cheers,

Apiparn Borisuit

EPFL ENAC ICARE LESO-PB
LE 001 (Bâtiment LE)
Station 18
CH-1015 Lausanne

Téléphone +4121 69 36265 <callto:+41216936265>

Fax +4121 69 32722

*From:* [email protected]
[mailto:[email protected]] *On Behalf Of
*Jan Wienold
*Sent:* lundi, 11. octobre 2010 11:18
*To:* Radiance general discussion
*Subject:* Re: [Radiance-general] Evalglare - Luminance or Illuminance

Hi Apiparn,

the main thing is, that for the DGP the vertical illuminance at eye
level is needed. Evalglare calculates this value from the given image
and needs therefore the full 180°!

In case you are using a camera, which does not cover the full 180°,
you can also measure the vertical illuminance and feed this
illuminance value by using the -i option. In case you are using a
non-fish-eye lens and evalglare is blocking another view than -vta, I
could send you another version until the next release will be put
online. Within the next release, all view types will be allowed.

Cheers,

Jan

Borisuit Apiparn wrote:

Hi Jan,

According to your previous reply about the needed view (180° fisheye --vta) for EVALGLARE, why can't we use 120° to 140°, due to the human field of view?
Sorry if it is a redundant question. I 'm just new in the list.

Cheers,

Apiparn

Jan wrote:

Hi Andrew,

yes, evalglare needs a 180° fish-eye(-vta)- LUMINANCE image. Internally
it calculates the vertical illuminance as Greg mentioned before.

A value of 0.4756 is a rather high value (-> 48% are disturbed by glare).

At the last building simulation conference, I suggested some "glare
classes" based on user assessments, which may help to interpret the DGP
values.
(table 5 in http://www.ibpsa.org/proceedings/BS2009/BS09_0944_951.pdf ).
Further details can be found also in my dissertation "Daylight Glare in
Offices", which will be available in some days as pdf on our web-site.

Cheers,

Jan

------------------------------------------------------------------------

_______________________________________________
Radiance-general mailing list
[email protected] <mailto:[email protected]>
http://www.radiance-online.org/mailman/listinfo/radiance-general
  
--
Dr.-Ing. Jan Wienold
Project Manager
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings, Lighting and Daylighting
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected] <mailto:[email protected]>
http://www.ise.fraunhofer.de

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30
------------------------------------------------------------------------

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
  
--
Dr.-Ing. Jan Wienold
Project Manager
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings, Lighting and Daylighting
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected]
http://www.ise.fraunhofer.de

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30

9

Thank you very much, Jan.
It is very clear.

Cheers,
Apiparn Borisuit

EPFL ENAC ICARE LESO-PB
LE 001 (Bâtiment LE)
Station 18
CH-1015 Lausanne
Téléphone +4121 69 36265<callto:+41216936265>
Fax +4121 69 32722

···

From: [email protected] [mailto:[email protected]] On Behalf Of Jan Wienold
Sent: lundi, 11. octobre 2010 12:23
To: Radiance general discussion
Subject: Re: [Radiance-general] Evalglare - Luminance or Illuminance

Hi Apiparn,

if you use the -i option, you need to measure the vertical illuminance and you should do that as close to the lense as possible ! In that case, evalglare will use the value provided by -i as vertical illuminance.

if you don't use the -i option and provide an image smaller than 180°, then the vertical illuminance will be less than the real value and this might have an significant influence, depending on the situation!

The detection of the glare sources and the calculation of the contribution of the glare sources to the DGP are only influenced minor when you use a smaller view angle than 180°.

In case of DGI and UGR you don't need a 180° image. Be careful when trying to evaluate these glare metrics - especially that the parameters for the detection of the glare sources fit to your scenes and that this fits also to the validity ranges of the equations! (e.g. DGI is only defined for a window as glare source and the UGR is valid only for medium sized solid angles of the artifical glare source). Always check by using -c option, if the "correct" glare sources are detected, when using other glare metric than DGP! The DGP is very robust concerning the detection parameters since the main contribution comes from the vertical eye illuminance (except you have the sun or a specular reflection of it in the field of view).

Cheers,

Jan

Borisuit Apiparn wrote:
Hi Jan,

Thanks a lot for your quick reply.
If I use the -i option (~120° -with fisheye lens), will the vertical illuminance be much different with the image of 180° view?
Moreover , for calculating DGI or UGR by Evalglare, we don't need the full 180° ?

Cheers,
Apiparn Borisuit

EPFL ENAC ICARE LESO-PB
LE 001 (Bâtiment LE)
Station 18
CH-1015 Lausanne
Téléphone +4121 69 36265<callto:+41216936265>
Fax +4121 69 32722

From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Jan Wienold
Sent: lundi, 11. octobre 2010 11:18
To: Radiance general discussion
Subject: Re: [Radiance-general] Evalglare - Luminance or Illuminance

Hi Apiparn,

the main thing is, that for the DGP the vertical illuminance at eye level is needed. Evalglare calculates this value from the given image and needs therefore the full 180°!

In case you are using a camera, which does not cover the full 180°, you can also measure the vertical illuminance and feed this illuminance value by using the -i option. In case you are using a non-fish-eye lens and evalglare is blocking another view than -vta, I could send you another version until the next release will be put online. Within the next release, all view types will be allowed.

Cheers,

Jan

Borisuit Apiparn wrote:
Hi Jan,

According to your previous reply about the needed view (180° fisheye -vta) for EVALGLARE, why can't we use 120° to 140°, due to the human field of view?

Sorry if it is a redundant question. I 'm just new in the list.

Cheers,

Apiparn

Jan wrote:

Hi Andrew,

yes, evalglare needs a 180° fish-eye(-vta)- LUMINANCE image. Internally

it calculates the vertical illuminance as Greg mentioned before.

A value of 0.4756 is a rather high value (-> 48% are disturbed by glare).

At the last building simulation conference, I suggested some "glare

classes" based on user assessments, which may help to interpret the DGP

values.

(table 5 in http://www.ibpsa.org/proceedings/BS2009/BS09_0944_951.pdf ).

Further details can be found also in my dissertation "Daylight Glare in

Offices", which will be available in some days as pdf on our web-site.

Cheers,

Jan

________________________________

_______________________________________________

Radiance-general mailing list

[email protected]<mailto:[email protected]>

http://www.radiance-online.org/mailman/listinfo/radiance-general

--

Dr.-Ing. Jan Wienold

Project Manager

Fraunhofer-Institut für Solare Energiesysteme

Thermal Systems and Buildings, Lighting and Daylighting

Heidenhofstr. 2, 79110 Freiburg, Germany

Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133

[email protected]<mailto:[email protected]>

In office:

Mo,Tue: 8:30-18:00

We,Thu: 8:30-16:00

Fr: 8:30-15:30

________________________________

_______________________________________________

Radiance-general mailing list

[email protected]<mailto:[email protected]>

http://www.radiance-online.org/mailman/listinfo/radiance-general

--

Dr.-Ing. Jan Wienold

Project Manager

Fraunhofer-Institut für Solare Energiesysteme

Thermal Systems and Buildings, Lighting and Daylighting

Heidenhofstr. 2, 79110 Freiburg, Germany

Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133

[email protected]<mailto:[email protected]>

In office:

Mo,Tue: 8:30-18:00

We,Thu: 8:30-16:00

Fr: 8:30-15:30

10

Hi Andrew,

you can download now the pdf-file of my dissertation now here:

http://www.ise.fraunhofer.de/veroeffentlichungen/nach-jahrgaengen/2010/buecher-und-beitraege-zu-buechern/dayligth-glare-in-offices

The layout is in A5, the font may appear large if you print it on A4 or
letter size.
If you want a printed version, you can order it also in any on-line
bookshop.

Cheers,

Jan

Bissell, Andrew wrote:

···

Thanks Jan, very much appreciate the quick response. I look forward
to reading your dissertation.

Regards

Andrew

__________________________
*Andrew Bissell*

B.Eng(Hons) C.Eng MSLL MCIBSE MIET
Associate Lighting Designer

Cundall *Light4*
Direct: 0161 200 1235
Mobile: 07899 907 978

Office: 0161 244 5660

P Please consider the environment before printing this e-mail

*From:* [email protected]
[mailto:[email protected]] *On Behalf Of
*Jan Wienold
*Sent:* 04 October 2010 17:23
*To:* Radiance general discussion
*Subject:* Re: [Radiance-general] Evalglare - Luminance or Illuminance

Hi Andrew,

yes, evalglare needs a 180° fish-eye(-vta)- LUMINANCE image.
Internally it calculates the vertical illuminance as Greg mentioned
before.

A value of 0.4756 is a rather high value (-> 48% are disturbed by glare).

At the last building simulation conference, I suggested some "glare
classes" based on user assessments, which may help to interpret the
DGP values.
(table 5 in http://www.ibpsa.org/proceedings/BS2009/BS09_0944_951.pdf
). Further details can be found also in my dissertation "Daylight
Glare in Offices", which will be available in some days as pdf on our
web-site.

Cheers,

Jan

Greg Ward wrote:

Hi Andrew,

You definitely want a luminance image -- using -i would give you wrong results. Evalglare should add up luminances with the appropriate weighting to get vertical illuminance at the eye.

Cheers,
-Greg

    From: "Bissell, Andrew" <[email protected]> <mailto:[email protected]>

    Date: October 2, 2010 1:07:53 PM PDT

    Sorry for what must be obvious questions. I have just compiled evalglare for Linux and I have run a few test images albeit the images were very low res. I have read various papers and posts on the net and seen the images referred to as luminance images and illuminance images. So which is it? Part of me says luminance as brightness is more relative to glare, on the other hand my understanding of DGP is that it measures illuminance at the eye. Which led to me confusing myself over the type of image required. Certainly if you try both, the results are different, however the images I am using are crude with just 1 bounce so that could easily explain the difference.

    Also I read the luxeuropa2005.pdf on the evaluation method etc. However I was still at a loss as to what the DGP results really meant. E.g. if the DGP result is 0.4756 what does that mean. The document talked about levels below 0.2 not being reliable.

    The other evalglare posts were useful wrt –vth and –vta, also the picture header. Thank you.

    Regards

    Andrew

_______________________________________________
Radiance-general mailing list
[email protected] <mailto:[email protected]>
http://www.radiance-online.org/mailman/listinfo/radiance-general
  
--
Dipl.-Ing. Jan Wienold
Project Manager
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings, Lighting and Daylighting
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected] <mailto:[email protected]>
http://www.ise.fraunhofer.de

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30
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Cundall Johnston & Partners LLP is a limited liability partnership
registered in England and Wales. Registered number OC300389.
Registered office: Horsley House, Regent Centre, Gosforth, Newcastle
upon Tyne, NE3 3LU
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--
Dr.-Ing. Jan Wienold
Project Manager
Fraunhofer-Institut für Solare Energiesysteme
Thermal Systems and Buildings, Lighting and Daylighting
Heidenhofstr. 2, 79110 Freiburg, Germany
Phone: +49(0)761 4588 5133 Fax:+49(0)761 4588 9133
[email protected]

In office:
Mo,Tue: 8:30-18:00
We,Thu: 8:30-16:00
Fr: 8:30-15:30