Talk:Reflectance

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This article is way too technical, full of scientific jargon and Greek characters.

Wikipedia is supposed to be for a lay audience, not just for people with Ph.D. degrees in math and physics. I can't make heads nor tails out of the jargon-filled explanations. — Preceding unsigned comment added by 172.91.176.10 (talk) 03:31, 24 February 2019 (UTC)Reply

That section reads a lot like an advertisement, and should be further edited.

I agree. Incidentally, the reference at the following link is surprisingly the only one I found that put experimental points on the Fresnel equations on a FLAT water surface! http://journals.ametsoc.org/doi/pdf/10.1175/2007JTECHA1049.1

I think it could be cited at the end of the sentence "That part of incident light that is reflected from a body of water is specular and is calculated by the Fresnel equations." Yet, the sentence should be changed to : "The specular portion of incident light reflected from a body of water is calculated by the Fresnel equations." —Preceding unsigned comment added by 68.193.231.122 (talk) 05:09, 21 April 2011 (UTC)Reply

Should the following be added? If so, where?

That part of incident light that is reflected from a body of water is specular and is calculated by the Fresnel equations. Fresnel reflection is directional and therefore does not contribute significantly to albedo which is primarily diffuse reflection. A graph showing the reflectivity of water vs. incident angle of can be seen at[1].

A real water surface may be wavy. Reflectance assuming a flat surface as given by the Fresnel equations can be adjusted to account for waviness. A formula and graph for correction for waviness for two different wave energy spectrum definitions exists. ^[1] 4.232.0.81 02:39, 11 August 2006 (UTC)Reply

This is currently the Reflectivity and Reflectance article -- it should say so right at the top.-69.87.202.60 11:49, 17 May 2007 (UTC)Reply

I am inclined to delete this entire section and replace it with a more accurate definition of reflectance, unless somebody can provide a reference for where this definition of reflectance originates. Bulk reflectivity is not called reflectance any more than thin film reflectance is called reflectivity. They are two fundamentally different, albeit related quantities. In any case, I will provide the proper optical/physical definition of reflectivity and reflectance. —Preceding unsigned comment added by Nanoguitar (talk • contribs) 20:17, 28 May 2008 (UTC)Reply

Reflectance vs. wavelength curves for aluminium (Al), silver (Ag), and gold (Au) metal mirrors

This is a nice graph; might be nice to also have it in the mirror article. It would be of more general use if the bounds of visible light could be added.-69.87.202.60 11:52, 17 May 2007 (UTC)Reply

This article is a good theoretical start, but needs a lot more real-world data.

Please add typical range of total visible-light reflectivity for ordinary mirrors (80%?), white paper (up to at least 90%?), other ordinary white surfaces, and ordinary black surfaces. And spectral curves for all of those, too, from UV to IR, with the visible portion clearly marked.

And, links to great sources of such details.-69.87.202.60 11:59, 17 May 2007 (UTC)Reply

This seems to be the pure physics term/concept. In dealing with light, much of the terminology is weighted by the response of the human eye to different colors (Lumens, for example). What is the term for reflectance, weighted in the visible spectrum by the human visual response? It should be at least mentioned in this article, and linked to.-69.87.204.232 11:26, 19 May 2007 (UTC)Reply

Photopic spectral responsivity (cf. Color vision#Physiology of color perception) --Adoniscik (talk) 00:19, 7 February 2008 (UTC)Reply

• Colors

70-80% White

70-80% Light cream

55-65% Light yellow

45-50% Light green

45-50% Pink

40-45% Sky-blue

40-45% Light grey

25-35% Beige

25-35% Yellow ocher

25-35% Light brown

25-35% Olive green

20-25% Orange

20-25% Vermilion red

20-25% Medium grey

10-15% Dark green

10-15% Dark blue

10-15% Dark red

10-15% Dark grey

• Materials

95% Mirror

80% Plaster

65-75% White enamel

60-75% Glazed white tiles

60% Maple

60% Birch

40% Light oak

15-20% Dark oak

15-20% Dark walnut

15-40% Concrete

5-25% Red brick

2-10% Carbon-black

6-8% Clear glass

• Lighting design

60-90% Ideal Ceilings

35-60% Ideal Walls

30-50% Ideal Countertops

-69.87.203.133 01:04, 25 May 2007 (UTC)Reply

Link (1) is broken. 128.12.103.70 (talk) 15:45, 14 December 2007 (UTC)Reply

I think the unit(s) of reflectivity must be mentioned. --Sylvestersteele (talk) 12:02, 10 February 2008 (UTC)Reply

Reflectivity is unitless. Stonemason89 (talk) 02:21, 10 March 2010 (UTC)Reply

i think i read somewhere that it's silver

but i think some other guys said it's rhodium

reflectivity is a function of frequency, we get that part

but if you have some standard light source, say sunlight at some place, then it's just a number —Preceding unsigned comment added by 65.107.1.165 (talk) 20:57, 24 November 2009 (UTC)Reply

Rhodium is not particularly shiny. Silver is the shiniest metal when averaged across the entire visible spectrum, but it is exceeded in some parts of the spectrum by tin and aluminum. Stonemason89 (talk) 17:01, 6 March 2010 (UTC)Reply

I'm not convinced that the distinction made in this article between "reflectivity" and "reflectance" is universal. I don't doubt that some authors define the terms that way, but unless all do the article should be less strongly worded. --Srleffler (talk) 03:24, 29 April 2010 (UTC)Reply

Agreed; modified. Fgnievinski (talk) 20:39, 7 May 2015 (UTC)Reply

This page is redirected from "absorptance", but doesn't mention it. It does say "see also absorptivity", but the absorptivity page just says absorptivity means absorptance, which redirects here. This page should at the very least give a definition of absorptance/absorptivity, and discuss how it relates to reflectivity. Either that or there should be a separate page.

Additionally, if anyone has a good idea of how the concepts of absorptance, reflectance and emissivity relate to the concept of albedo, it would be very helpful to update this page with some details.

125.7.18.1 (talk) 01:28, 22 September 2011 (UTC)Reply

The comment(s) below were originally left at Talk:Reflectance/CommentsTalk:Reflectance/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

merge to colorimetry

Substituted at 01:11, 12 June 2016 (UTC)