![]() | This ![]() It is of interest to the following WikiProjects: | ||||||||||
|
![]() | It is requested that a physics diagram or diagrams be
included in this article to
improve its quality. Specific illustrations, plots or diagrams can be requested at the
Graphic Lab. For more information, refer to discussion on this page and/or the listing at Wikipedia:Requested images. |
The following was removed:
The solid angle in radiance means a range of impulses of the particles involved. For small angles this impulse is transverse to a main impulse, but in the same direction as the area. The product is bound by the uncertainty principle. The minimal product is achieved by lasers.
This needs to use more standard terminology. I cannot even imagine what is trying to be conveyed here. PAR 18:01, 3 February 2007 (UTC)
For a beam of a given solid angle there is a range of momenta of the photons involved. For small angles, the momentum of each photon may be divided up into a large momentum component in the direction of travel, and small deviations perpendicular to the direction of travel. The product of these deviations times the width of a beam is bound by the uncertainty principle. The minimal product is achieved by a laser beam.
How does this fit in with Luminance? 5:22a 19 Apr 2007 (UTC)
Hi: Shouldn't someone add that W/sr/m3 is commonly called a "flick?" Thanks Donicecapade 17:22, 18 June 2007 (UTC)
The meaning could be explained better by someone who really understands it. As I understand it, the importance of radiance is how concentrated a light source is and so its ability to damage the retina. For example, an incandescent bulb with clear glass would have higher radiance than a "soft" bulb with the same irradiance in that the "soft" bulb releases its light over a greater spherical angle from the point of view of an observer. Is that right? 155.212.242.34 19:37, 3 December 2007 (UTC)
It is unlikely that Irradiance page can be expanded beyond two paragraphs, so is the case with other radiometric quantities. I suggest we should merge article related radiometric quantities under one article such as Radiometric quantities with one sub-section for each quantities. This will also make it easy to create equations where notations are shared across several definitions. pruthvi ( talk) 14:24, 8 March 2008 (UTC)
Moved following out of article. -- Srleffler ( talk) 23:11, 15 May 2008 (UTC)
A cosine term in the denominator would imply infinite radiance for an angle of incidence of 90° from the plane-normal. Is this physical? —Preceding unsigned comment added by Deathmare ( talk • contribs) 13:55, 22 May 2009 (UTC)
I have proposed to merge Intensity (heat transfer) into this article, because the former explicitly states that radiance is an alternate name for the same thing, and indeed they appear to be the same physical quantity. Wikipedia articles are organized by topic, not by name. When one thing has two names, both are covered in a single article. This is related to the fact that Wikipedia is an encyclopedia, not a dictionary.-- Srleffler ( talk) 04:23, 21 October 2008 (UTC)
There are a number of poorly worded/communicated ideas in this article that lead the reader to an incomplete/erroneous understanding of this key measure of an optical system. These should be fixed. There should be a mention of the term "brightness," a common substitute term. There should be a mention of the limitations nature places on the brightness, measured in an optical system (irradiance does not have this restriction). As light travels further from the source, and through any optical elements, the further along the optical system that the measurements are made, the brightness must always (well, except for some very special cases) fall to successively lower values. blackcloak ( talk) 03:52, 27 May 2009 (UTC)
Slight Error? The body of the text has "This means that for an ideal optical system in air, the radiance at the output is the same as the input radiance."
I suspect the author intended this for radiation "in a vacuum" rather than "in air."
Would a knowledgeable person please check this and correct it if so, and explain why there is no loss in radiance in air - if not. —Preceding unsigned comment added by 69.22.179.156 ( talk) 20:57, 24 February 2011 (UTC)
What is "D" in the formula ? Is this delta ? or distance ? or something else ? It's not in the legend... — Preceding unsigned comment added by 84.25.172.195 ( talk) 14:13, 29 December 2011 (UTC)
It's not clear to me what is that square factor doing in the equation of L:
Shouldn't it be simply:
Can someone give a reason for that factor? Gaba p ( talk) 14:59, 17 April 2012 (UTC)
Yes, do you see a substantial difference between those two ways of writing that equation? I don't think it matters which side of the equation the differentials are. Gaba p ( talk) 17:57, 19 April 2012 (UTC)
The note accompanying Radiance in the table says "per unit projected source area" (my italics). Granted there is a symmetry between the projecting and projected area, but when considering radiation emitted from an arbitrarily shaped surface into space, with no particular absorber in mind (e.g. the situation described by Planck's law), doesn't it make more sense to use area for the emitter (hence the projecting area) and solid angle dΩ for the divergence of the radiation leaving an infinitesimal area dA? If radiometry is supposed to be neutral about the light field source and sink then "projected area" doesn't seem sufficiently neutral in that regard. -- Vaughan Pratt ( talk) 10:09, 2 May 2012 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Radiance. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
This message was posted before February 2018.
After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than
regular verification using the archive tool instructions below. Editors
have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the
RfC before doing mass systematic removals. This message is updated dynamically through the template {{
source check}}
(last update: 5 June 2024).
Cheers.— InternetArchiveBot ( Report bug) 17:32, 22 January 2018 (UTC)
An editor has asked for a discussion to address the redirect Orders of magnitude (radiance). Please participate in the redirect discussion if you wish to do so. Utopes ( talk / cont) 20:33, 8 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Watt per steradian per square metre. Please participate in the redirect discussion if you wish to do so. Utopes ( talk / cont) 20:33, 8 April 2020 (UTC)
At Talk:Specific radiative intensity#Requested move 8 October 2022 I have proposed that we rename that article Spectral radiance and move content on that topic from this article to that one. "Specific radiative intensity" is a synonym for "spectral radiance", and Wikipedia is not a dictionary—we need one article per topic. Srleffler ( talk) 22:54, 8 October 2022 (UTC)
![]() | This ![]() It is of interest to the following WikiProjects: | ||||||||||
|
![]() | It is requested that a physics diagram or diagrams be
included in this article to
improve its quality. Specific illustrations, plots or diagrams can be requested at the
Graphic Lab. For more information, refer to discussion on this page and/or the listing at Wikipedia:Requested images. |
The following was removed:
The solid angle in radiance means a range of impulses of the particles involved. For small angles this impulse is transverse to a main impulse, but in the same direction as the area. The product is bound by the uncertainty principle. The minimal product is achieved by lasers.
This needs to use more standard terminology. I cannot even imagine what is trying to be conveyed here. PAR 18:01, 3 February 2007 (UTC)
For a beam of a given solid angle there is a range of momenta of the photons involved. For small angles, the momentum of each photon may be divided up into a large momentum component in the direction of travel, and small deviations perpendicular to the direction of travel. The product of these deviations times the width of a beam is bound by the uncertainty principle. The minimal product is achieved by a laser beam.
How does this fit in with Luminance? 5:22a 19 Apr 2007 (UTC)
Hi: Shouldn't someone add that W/sr/m3 is commonly called a "flick?" Thanks Donicecapade 17:22, 18 June 2007 (UTC)
The meaning could be explained better by someone who really understands it. As I understand it, the importance of radiance is how concentrated a light source is and so its ability to damage the retina. For example, an incandescent bulb with clear glass would have higher radiance than a "soft" bulb with the same irradiance in that the "soft" bulb releases its light over a greater spherical angle from the point of view of an observer. Is that right? 155.212.242.34 19:37, 3 December 2007 (UTC)
It is unlikely that Irradiance page can be expanded beyond two paragraphs, so is the case with other radiometric quantities. I suggest we should merge article related radiometric quantities under one article such as Radiometric quantities with one sub-section for each quantities. This will also make it easy to create equations where notations are shared across several definitions. pruthvi ( talk) 14:24, 8 March 2008 (UTC)
Moved following out of article. -- Srleffler ( talk) 23:11, 15 May 2008 (UTC)
A cosine term in the denominator would imply infinite radiance for an angle of incidence of 90° from the plane-normal. Is this physical? —Preceding unsigned comment added by Deathmare ( talk • contribs) 13:55, 22 May 2009 (UTC)
I have proposed to merge Intensity (heat transfer) into this article, because the former explicitly states that radiance is an alternate name for the same thing, and indeed they appear to be the same physical quantity. Wikipedia articles are organized by topic, not by name. When one thing has two names, both are covered in a single article. This is related to the fact that Wikipedia is an encyclopedia, not a dictionary.-- Srleffler ( talk) 04:23, 21 October 2008 (UTC)
There are a number of poorly worded/communicated ideas in this article that lead the reader to an incomplete/erroneous understanding of this key measure of an optical system. These should be fixed. There should be a mention of the term "brightness," a common substitute term. There should be a mention of the limitations nature places on the brightness, measured in an optical system (irradiance does not have this restriction). As light travels further from the source, and through any optical elements, the further along the optical system that the measurements are made, the brightness must always (well, except for some very special cases) fall to successively lower values. blackcloak ( talk) 03:52, 27 May 2009 (UTC)
Slight Error? The body of the text has "This means that for an ideal optical system in air, the radiance at the output is the same as the input radiance."
I suspect the author intended this for radiation "in a vacuum" rather than "in air."
Would a knowledgeable person please check this and correct it if so, and explain why there is no loss in radiance in air - if not. —Preceding unsigned comment added by 69.22.179.156 ( talk) 20:57, 24 February 2011 (UTC)
What is "D" in the formula ? Is this delta ? or distance ? or something else ? It's not in the legend... — Preceding unsigned comment added by 84.25.172.195 ( talk) 14:13, 29 December 2011 (UTC)
It's not clear to me what is that square factor doing in the equation of L:
Shouldn't it be simply:
Can someone give a reason for that factor? Gaba p ( talk) 14:59, 17 April 2012 (UTC)
Yes, do you see a substantial difference between those two ways of writing that equation? I don't think it matters which side of the equation the differentials are. Gaba p ( talk) 17:57, 19 April 2012 (UTC)
The note accompanying Radiance in the table says "per unit projected source area" (my italics). Granted there is a symmetry between the projecting and projected area, but when considering radiation emitted from an arbitrarily shaped surface into space, with no particular absorber in mind (e.g. the situation described by Planck's law), doesn't it make more sense to use area for the emitter (hence the projecting area) and solid angle dΩ for the divergence of the radiation leaving an infinitesimal area dA? If radiometry is supposed to be neutral about the light field source and sink then "projected area" doesn't seem sufficiently neutral in that regard. -- Vaughan Pratt ( talk) 10:09, 2 May 2012 (UTC)
Hello fellow Wikipedians,
I have just modified one external link on Radiance. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
This message was posted before February 2018.
After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than
regular verification using the archive tool instructions below. Editors
have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the
RfC before doing mass systematic removals. This message is updated dynamically through the template {{
source check}}
(last update: 5 June 2024).
Cheers.— InternetArchiveBot ( Report bug) 17:32, 22 January 2018 (UTC)
An editor has asked for a discussion to address the redirect Orders of magnitude (radiance). Please participate in the redirect discussion if you wish to do so. Utopes ( talk / cont) 20:33, 8 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Watt per steradian per square metre. Please participate in the redirect discussion if you wish to do so. Utopes ( talk / cont) 20:33, 8 April 2020 (UTC)
At Talk:Specific radiative intensity#Requested move 8 October 2022 I have proposed that we rename that article Spectral radiance and move content on that topic from this article to that one. "Specific radiative intensity" is a synonym for "spectral radiance", and Wikipedia is not a dictionary—we need one article per topic. Srleffler ( talk) 22:54, 8 October 2022 (UTC)