[at-l] So, if...

[camojack at comcast.net (camojack@comcast.net)]

Gotta love a smartass. No, really! :-)
-"Camo"

-------------- Original message -------------- 

> Well, since you axed: 
> 
> In general, ?brightness? is an expression of the 
> amount of light emitted from a surface per unit of 
> area. 
> ?Brightness? is not an official term of the lighting 
> trade, 
> and lighting designers may become huffy when you use 
> it. However, the concept is essential for 
> understanding 
> visual quality, especially in relation to contrast and 
> glare. 
> Brightness does not inherently relate to lamps, or 
> even to light sources. The light could be reflected or 
> transmitted. For example, the bright surface could be 
> the surface of a fluorescent tube, a page of a book, a 
> window with a view of the sky, or a store window with 
> reflections. 
> The closest official term is ?luminance,? which is 
> expressed as candelas per square meter of light 
> emitting 
> surface. (Luminance used to be measured in 
> ?footlamberts,? which is now an obsolete term.) For 
> example, the luminance of a heavily overcast sky is 
> about 
> 1,000 candelas per square meter, and the luminance of 
> a typical frosted light bulb is about 100,000 candelas 
> per square meter. 
> Luminance is defined in terms of the direction of 
> light emission. The details get technical, and you 
> probably will not need to deal with them. In brief, 
> the 
> brightness of an object usually depends on the 
> direction 
> from which you look at it. 
> Note that luminance has nothing to do with size of 
> the light emitting surface. The light source could be 
> as 
> small as a lamp filament, or it could be as large as 
> the 
> whole sky, or it could be a task area, such as a desk 
> top. 
> Measuring brightness (?luminance?) is tricky and 
> requires specialized equipment. For practical work, 
> learn how to avoid excessive brightness, so you won?t 
> need to measure it. If you do a good job of laying out 
> lighting, people within the space will not be 
> subjected 
> to brightness that is severe enough to cause glare. 
> Luminance is the converse of illuminance. The 
> former describes the intensity of light that is 
> leaving a 
> surface, whereas the latter describes the intensity of 
> light 
> that is falling on a surface. For light reflected from 
> a 
> surface, luminance equals illuminance multiplied by 
> the 
> percentage of reflectance. 
> ?Brightness? also is used to describe the subjective 
> sensation of light intensity. This sensation largely 
> depends on the overall layout of the scene surrounding 
> the viewer. An uncomfortable level of brightness is 
> described as ?glare.? (The term ?glare? is used in 
> several 
> ways. It is an important concept, but is not precisely 
> defined by the lighting trade. Various types of glare 
> are 
> explained in Reference Note 51, Factors in Lighting 
> Quality.) 
> In Summary ... 
> So, here is the overall picture. A lamp produces a 
> certain amount of light, measured in lumens. This 
> light 
> falls on surfaces with a density that is measured in 
> footcandles or lux. A person looking at the scene sees 
> different areas of his visual field in terms of levels 
> of 
> brightness, or luminance, measured in candelas per 
> square meter. 
> 
> Now aren't you sorry that you ever brought it up? 
> 
> --- Felix wrote: 
> 
> > So, if something is '10 Times Brighter' than 
> > something else...could it also be 
> > said that it is 1/10th as dim? 
> 
> 
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> http://mailman.backcountry.net/mailman/listinfo/at-l From spiriteagle99 at hotmail.com  Fri Sep 23 14:13:53 2005
From: spiriteagle99 at hotmail.com (Jim and/or Ginny Owen)
Date: Fri Sep 23 15:16:14 2005
Subject: [at-l] The Gathering
Message-ID: <BAY104-F12454ECE529572D8486A34A0960@phx.gbl>

Saunterer said that he was worried that there might not be enough 
interesting workshops to make the long drive and gas expense worthwhile.

The Gathering Schedule is usually not posted online until very close to the 
time of the Gathering, sometimes only two or three days ahead.  People are 
often still volunteering up to the day the Gathering starts and it is a very 
intricate feat to juggle dozens of workshops with the times and rooms 
available. (Everyone wants to present on Saturday - nobody wants Sunday 
afternoon.) The coordinators try to avoid having competing workshops - but 
never really succeed.  One thing to remember is that Hanover always has a 
lot more workshops offered than Pipestem.  I don't know why, but that has 
been consistent over the past 10 years or so that I've been attending.  
Maybe New Englanders have a better volunteer spirit?

I also really enjoy the workshops.  I love the slideshows, seeing pictures 
of beautiful places I may someday hike or have already hiked, and I enjoy 
hearing presentations on trails that I want to learn more about.  Sometimes 
I go to workshops on trails I've hiked in order to refresh my memories or 
join in the discussion, sometimes I go to trails that I will probably never 
hike, just to see if they can change my mind.  Some of the discussion forums 
have been really interesting.  I never get to see all the workshops I would 
like to see, because there are so many options.  And sometimes my option is 
simply to sit in the sun with a couple of friends to chat.

I go to the Gathering for a lot of reasons -- number one is to be with 
people who KNOW what long distance hiking is about, to see old friends and 
make new ones  -- but I also go to learn -- and I always learn something 
new.  I also go to be inspired, and hopefully to inspire in my turn.  That 
happens both through the workshops and slideshows and the discussion that go 
with them, and also through the people we get to meet.

I understand the money issue - it's a long drive up to Hanover and gas 
prices aren't likely to go down over the next few weeks - but I won't miss 
the Gathering.  Having the chance to spend time with folks who really 
understand is too rare in my life.

Ginny

http://www.spiriteaglehome.com/