IDA-Colorado section news and upcoming events
Monthly IDA-Colorado pow-wows during Open House nights at U of Denver's historic Chamberlin Observatory 

8-10pm weather permitting including 2017 July 15 and TBA. 

for updates: www.twitter.com/Chamberlin_Obs .


Lighting codes/regulations in your area (2014): http://www.iescu.org/lightingcodes.htm


				2014 to the present ...  communications with colorado.ida AT gmail.com
				& we have a Facebook page!  https://www.facebook.com/ColoradoIDA 
Dark Sky Meter phone app: http://www.darkskymeter.com/ 
Map of DarkSkyMeter app readings including Colorado: http://www.darkskymeter.com/map/ 
and the original and best SkyQualityMeter [SQM]: http://unihedron.com/projects/darksky/ 
	although SQM is LED blue-blind
	but there are several phone apps simulate SQM: Lux Meter (android), Lux-o-Meter (windows)

2018 Winter/Spring

New contacts with the Pueblo CO dark sky advocates who are part of the So Colo Astron Society ( http://www.scaspueblo.com/ , aknight@scaspueblo.com )

Had a chat about space and light pollution solutions with first graders at the Rocky Mountain School for Expeditionary Learning - charming, bright bunch!

2017 Summer/Fall

We were invited to address a meeting of statewide code enforcement officers in September, on topics including measuring lighting, direct rays versus glare, and related.

Colorado section finally met as a group on 15 July at DU's historic Chamberlin Observatory.  News: we have a Facebook page!  https://www.facebook.com/ColoradoIDA 

Denver city explores contract changes with Xcel Energy to replamp streetlights with LEDs - the discussion will involve lamp temperature ("high Kelvin" versus lower Kelvin). Pilot project areas include: Union Station (3500K lamps), 32nd west of Peco (Highlands, 4000K harsh!), area around RTD station 51st & Pena (3000K) and plans to relamp Colfax west of York. Related info pages: http://www.darksky.org/lighting/3k/  and also SF plans: http://sfwater.org/index.aspx?page=933 .  Stay tuned and/or offer to help!

Sad news from remote Perry Park (SW corner of Douglas County, CO) - skyglow has gotten annoyingly bright due to unrestrained development throughout the Front Range cities - from Colo Springs to Denver and the inter-mountain towns expanding unsustainably... contact:  chrisdunmall at comcast.net

2017 March

Emergent interest in dark sky preservation, from a Douglas County group (Earth Night event, 4/22) 

...and a welcome statement by the American Astronomical Society about what you can do to help: 

https://aas.org/posts/news/ 2017/03/aas-council-issues- new-resolution-light-pollution   --

" Local action? Here are some ideas:
**If your city or town has not yet switched its streetlights to LEDs, quick! Contact your mayor, city councilor, 
planning office, and/or department of public works and make sure they know about the basic rules of good 
outdoor lighting (see above) before they make a mistake they'll be stuck with for 20 years. Emphasize the 
serious threats to human health that bad outdoor lighting poses: disruption of circadian rhythms, suppression 
of melatonin, and elevated rates of cancer, diabetes, and obesity. Give them the latest illustrated info brochures from the IDA.
**Form an outdoor lighting advisory committee in your city or town. Include not just astronomers, but also
 experts in, or at least people concerned about, public health, public safety, wildlife, and energy savings.
**Help draft an outdoor lighting ordinance that reflects current best practices, including proper treatment of LED
 lights. The IDA website has useful resources including a Model Lighting Ordinance — you don't have to start from scratch.  
**Get in touch with existing environmental organizations, such as local chapters of the Sierra Club, 
the Appalachian Mountain Club, The Nature Conservancy, etc., teach them about the importance of controlling
 light pollution for the health and welfare of wildlife, and enlist their aid in spreading the word.
**Contact the environmental studies, geography, architecture, and/or urban planning departments on your (or on
 a nearby) campus and educate them about the far-reaching hazards of light pollution and the importance of good outdoor lighting.
**Visit a local elementary, middle, or high school and teach kids about light pollution. The IDA and the Globe at Night 
citizen science program offer lots of good teaching resources." 


2017 Feb
Received notification of receipt of a Dark Sky Defender award being presented to Colorado IDA. :-) 

2016 Autumn
Developments of note: in addition to several calls from the public about light trespass issues, we noticed that a multi-year series of  
Unihedron Sky Quality Meter (SQM) readings made at DU's historic Chamberlin Observatory, were trending toward fainter.  
This contradicted what our eyes saw - a relentless increase in skyglow due to expanding night lighting in metro Denver. The 
discrepancy is thought to be due to the yellow sensitivity of the SQM, whereas the fastest increasing source of light is from LEDs 
with their strong blue light component - invisible to the SQM, but perceptible to our eyes.

New article of note (8 pages): https://www.theguardian.com/environment/2016/aug/23/why-we-need-darkness-light-pollution-stars

Called Nancy Clanton and she concurs that after a lot of effort last decade, mainly in the Greenprint Denver process, draft lighting regs were looking good... but once the then-Director left, the whole thing got shelved, leaving Denver city with essentially no lighting code. This cannot stand.  
Nancy also commented that she is trying to persuade Denver public works dept to go with lower color temperature LED streetlights, but Xcel wants hotter, non-dimmable variety.

20160819 - very welcomed visit by Dr. John Barentine, program manager at IDA. Spoke at the DAS general meeting about light pollution mitigations

20160315 - scheduled talk on light pollution solutions, 7pm at AnyThink! Library, 9417 Huron St., Thornton CO. https://www.facebook.com/events/1711660595716528/ 

20160120 - Well-received talk today on light pollution solutions, to the Mile High Chapter of Rotary International. About 40 persons in attendance. Good questions asked. Historic location, at the University Club, downtown Denver at 17th and Sherman Sts - an 1891 landmark that probably held an astronomy lecture (or several) by Denver's pioneer-era astronomer, Prof. Herbert Howe.

20151231 - end of year dialog with Fort Collins CO newspaper reporter Julie Dugdale, concerning efforts by FC environmental planning office to move toward meeting IDA dark-sky compliance. Among other topics, hit upon the notion that light pollution is akin to racism and sexism, in that all reflect thoughtlessness and ignorance.

20151121 - front page, Denver Post (circulation 250,000): http://www.denverpost.com/news/ci_29145158/night-light-woes-spur-colorado-push-restore-starry - "Front Range city planners are getting involved in efforts to control light pollution as residents increasingly push to see the Milky Way" - article by Bruce Finley, energy/environment reporter.

20151021 -- news from: Sherry Ellms, MA, Associate Professor Environmental Studies, Naropa University, Boulder, who wrote: "Regardless, as an FYI, I am presenting a workshop on Dark Skies at the Bioneers Conference at CU in Boulder.   Relying heavily on Bogard’s book [The End of Night] as well as the great website for IDA and my own personal connection to the topic.   Mainly I want to get people (if anyone shows up - there are several concurrent  interesting workshops) talking about dark skies and the importance of being able to see the stars. - The Importance and Joy of "Being in the Dark": How Light can blind us and fear can enlighten us.  What happens when we can no longer see the stars? If we lose our ability to experience dark skies, we lose the ability to experience the darkness within - the richness of the shadow, one of our greatest teachers. We lose our basic instinctual sense of place in the Universe.  We as a society, we are becoming afraid of the dark and think if we light up our streets and neighborhoods we are safer, but in fact we become more fearful—fearful of who and what we do not know. Light pollution, coming from commercial properties, offices, factories, street lights, sporting venues, has been linked to increasing energy consumption, disrupting ecosystems and wildlife, harming human health and negatively affecting crime and safety. Together, we will explore the psychological, physical, emotional and spiritual effects of light pollution and the joy of dark skies through lecture, story, guided exercises and poetry. Presented by Sherry Ellms of Naropa University.  I have had some conversations with Brett KitCairn the Senior Environmental Planner for the City of Boulder who has been helpful: see http://www.iescu.org/codes/City%20Ordinances/Boulder%20Illumination%20Ord%2009-15-2006.pdf 

2015 summer - several inquiries from homeowners concerning light trespass issues due to runaway development in their areas.

20150430 - New York City Plan to Save Energy May Mean a Dimmer Skyline - http://www.nytimes.com/2015/04/30/nyregion/new-york-plan-to-save-energy-may-mean-a-dimmer-skyline.html?_r=0 

20150416 -- IAU announces World Year of Light, Cosmic Light program addressing light pollution http://www.iau.org/news/pressreleases/detail/iau1504/ 

additionally, several good LP websites of note: http://www.iau.org/news/pressreleases/detail/iau1504/  -and- http://blue-marble.de/nightlights/2012                      http://www.skyandtelescope. com/get-involved/saving-dark- skies/?et_mid=742292&rid= 246434136     -and-   http://www.sustainableoutdoorlighting.com 

20150407 -- Greg Wimpey gwimpey@pobox.com wrote: "I’ve been doing some research on light pollution, and Google led me to a blurb on the Xcel website. Apparently, the Denver Highlands neighborhood is the site of a pilot program for installing LED streetlights. From the website: "In Denver, the LED streetlights on in the Highlands neighborhood, primarily bordered by West 33rd Avenue, I-25, Zuni Street and 16th street.” Here’s a link to the webpage: http://www.xcelenergy.com/Energy_Partners/Builders_&_Developers/Outdoor_Lighting/LED_Street_Lighting_Pilot_Project

Those and video signs are an increasing threat to any remaining signs of stars in metro Denver and the entire Front Range. You might find the IDA study on the blue light emission of LEDs of interest - attached.
Also, UVEX is marketing their orange goggles as a 'cure' for insomnia after reading device screens before bedtime... 
"Most evenings, before watching late-night comedy or reading emails on his phone, Matt Nicoletti puts on a pair of orange-colored glasses that he bought for $8 off the Internet.
“My girlfriend thinks I look ridiculous in them,” he said. But Mr. Nicoletti, a 30-year-old hospitality consultant in Denver, insists that the glasses, which can block certain wavelengths of light emitted by electronic screens, make it easier to sleep.
Studies have shown that such light, especially from the blue part of the spectrum, inhibits the body’s production of melatonin, a hormone that helps people fall asleep. Options are growing for blocking blue light, though experts caution that few have been adequately tested for effectiveness and the best solution remains avoiding brightly lit electronics at night. etc. --http://well.blogs.nytimes.com/2015/04/07/can-orange-glasses-help-you-sleep-better/ 

20150225 - setting aside legalities for a moment, there may be an opportunity to help find light pollution solutions with the use of DRONES.  Many property owners are unaware of the magnitude of escaped light, especially uplight.  However, a short video obtained in the evening by drone overflight could be a literal eye-opener...

20150121 - talk on LED lighting brought out the fact that Los Angeles has changed out their prior streetlight equipment in favor of LED luminaires - with resulting reduction in light escaping upward - see final frames in this pdf report: http://photos.state.gov/libraries/finland/788/pdfs/LED_Presentation_Final_June_2013.pdf 

20150115 - link to CDOT rules as adopted for Nighttime Video LED signage & see chron entries below.

20141024 - letter in support of dark sky designation for Colorado towns of Westcliffe and Silver Cliff:

Dark Skies, Inc., P.O. Box 634, Westcliffe, CO 81252

    On behalf of the Colorado Section of the IDA, I am writing in support of the nomination of the adjoining Towns of Westcliffe and Silver Cliff as the first International Dark-Sky Community in Colorado.  Approval will make these towns the highest in altitude of any designated.  It has been an inspiration to be aware of the local group, Dark Skies, that has been working diligently to reduce the light pollution of Colorado’s  wonderful “nightscape” of star-filled night skies. The protection of this valuable resource to both towns has been a 15-year journey of which both Dark Skies and the residents can be proud.  These towns serve as a crucial counter-example to the wanton and relentless destruction of dark skies occurring across much of Colorado.

    Viewing the nightscape from an isolated refuge and dark location like these Colorado towns can provide a transformative experience of unparalleled beauty.  This sense of awe, that most of human history has experienced, has been lost to urban dwellers.  Only through protection of remaining areas like Westcliffe-Silver Cliff, can residents and visitors continue to marvel at the view.  Because economics matter in success of this preservation effort, designation is key to promoting “eco-tourism” - which can become an important part of the towns’ economic success.  In parallel, the long-term protection of the nightscape is dependent on the towns’ enforcement of non-polluting, shielded exterior lighting language in their building ordinances.  Designation can help provide additional incentive for these towns to act to protect their special resource.

    Certification of the Towns of Westcliffe and Silver Cliff will also reduce the impact of light pollution on migrating and resident bird populations that use various aspects of the night sky for their instinctive behaviors.  It will also reduce the negative effects on the natural circadian rhythm of creatures, including humans, that are important for long-term health.  Urban dwellers need to wake up to these impacts on all living things within the zone caused by their excessive lighting and related pollutions.

    I am a proud supporter of Dark Skies’ certification effort for the Towns of Westcliffe and Silver Cliff.  It will reduce the impact of light pollution and I consider it as a transcendently  valuable example to all communities in Colorado to think and follow this path of light pollution solutions.

Astronomically,   Dr. Robert Stencel, Coordinator - Colorado section of IDA.

Success!  See http://www.darksky.org/assets/Night_Sky_Conservation/Communities/WSC_IDSC_press_release_FINAL.pdf  --contacts therein.

                * * * * *

20140906 - In Cities Across Texas, Activists Battle Billboard Companies
Text: http://www.npr.org/2014/09/06/346153394/in-cities-across-texas-activists-battle-billboard-companies  
Audio: javascript:NPR.Player.openPlayer(346153394, 346299218, null, NPR.Player.Action.PLAY_NOW, NPR.Player.Type.STORY, '0')   

"The Highway Beautification Act will be 50 years old next year. As envisioned by Lyndon and Lady Bird Johnson, it was supposed to protect the natural landscape from billboards.
"Ever since its passage, scenic activists and billboard companies have been at war over the views along American highways. The outdoor advertising industry says its signs are informational, and helpful to local businesses. Open-space advocates call them "sky trash" and "litter on a stick."
"The battle continues today. You can see it on the roads of Texas, where more than 350 towns and cities have banned new billboards — but billboard companies continue to push for taller and more technologically advanced signs. etc...

Notes related to the CDOT/electronic signage policy review meeting, 8-28-2014:  

    (1) strategically, although CDOT and State policy presently only cover "off-premise" electronic (LED) billboards, rules made at this level may be adopted by local jurisdictions to encompass the anticipated flood of similar signs "on premise" appearing at local businesses in your town.

    (2) how bright is an LED billboard capable of being?  Brightest in the region thus far are metro Denver signs adjacent to I-25 north at 58th street, with the brightest being 1,000 "nits" ... just how bright is that?  converting to magnitudes per sq.arcsecond (units of the type measured by a Sky Quality Meter), that equates to FIVE mags/sq.arcsec; for comparison, your laptop screen at max brightness might be about 60 "nits" or about 8 mag/sq.arcsec; for comparison, metro Denver SQM readings have been in the 16 to 18 mag/sq.arcsec ballpark, which equate to 3% to 10% of one cd/m2. 

    (3) if you see a overly bright electronic billboard at night, here's how to make an effective complaints: if it seems to be advertising an adjacent business, it may be an on-premises sign governed by local rules - contact the planning department or engineer of the town or city involved; if the sign appears to not be associated with an immediately nearby business, it may be an off-premises sign governed by state regs, in which case you can call the CDOT hotline, 303-757-9485, or online at dot AT state.co.us .   

    (4) Colorado section of the IDA believes documenting problems helps in their solution, and so we extend an invitation to submit your smart phone images of overly bright signs at night to the email address  colorado.ida AT gmail.com and be sure to include date, time, address and any information you have about the problem (e.g. glare or other disabling aspect).  We will try to share the digital info with appropriate authorities for resolution.

28 August 2014 -- CDOT & illumination levels from LED billboard signage - the latest source of glare for drivers and contributor to skyglow. Outdoor Advertising Rules Representative Group Meeting (rescheduled) to be held on August 28, 1pm, 4201 E. Arkansas Ave., Denver -- for more info , contact Mary Nevans, Rules Admin, 303-757-9723, maryfrances.nevans@ state.co.us.  Copies of related documents can be requested.

12 August 2014 -- email from Larry Barrett/ consultant with Scenic Colorado Inc. -- 

"I have left voicemail messages with Northern  Colo. Astronomical Society.  Denver Astronomical Society and  Colorado Springs Astronomical Society with Alan Gorski.  I left them messages this morning on the meeting plans of CDOT, encouraging them to register, and inviting them to call me.  If you have any connections with them and want to reinforce my message, please do.

"One objective of us should be for CDOT to not rush to judgment on nits vs. footcandles and levels, unless of course they agree on the use of nits and a level of 100 at night. I doubt they will adopt that.  However, I am concerned they may stick with their preliminary judgment in favor of footcandles and 0.3.  If they are still leaning that way I hope to persuade them to do more research, do not accept the limited research they have done, based largely on what has been submitted by the billboard industry and me.  If the rest of CDOT is using nits for highway lighting design, then why not for roadside advertising?   If CDOT has not done field testing of luminance and illuminance, it would seem good regulatory practice would be for CDOT to conduct independent research of existing static and electronic signs.

Thanks for your participation.

Larry Barrett, President, Barrett Consulting Associates, Inc., P.O. Box 60429, Colorado Springs, CO 80960, 719-634-4468 (o); 719-964-0825 (m)



11 August 2014 --Westcliffe and Silver Cliff applying for Dark Sky Community Certification --

 I just wanted to let you know that our Dark Skies group will be going public next month with our plans to seek IDA Dark Sky Community certification for Westcliffe and Silver Cliff (we are calling ourselves "The Cliffs" for this application).  As you may know our group has been quite active working on local dark skies projects for a number of years.  We believe we can already meet most of the IDA requirements for certification as a result of these activities.  Our primary hurdle will be to get the two communities to enact lighting ordinances to meet IDA requirements.
Westcliffe has hired a "Main Street Manager" to help with the community's economic development efforts.  Dark Sky Certification is expected to be one of this manager's first projects.  We will be giving a presentation to the Westcliffe Town Council at their meeting on September 8 to let them know what we are doing.  Once our plans are made public at this meeting I wouldn't be surprised if the press or others might contact IDA (and perhaps you as IDA coordinator) for more information.

As IDA's State Coordinator I am not sure how much you are involved in the certification process.  However, we certainly would like to solicit your support and guidance as we go through this.  I know some parks are working on certification but I do not know if any other Colorado communities are actively working on it at this time.

I will be serving as the IDA contact for our group.  Our current Chairman in Jim Bradburn.

If you would like to discuss this more I would be glad to call you (please let me know the best number to call).  You can also call me anytime at (719) 285-4480 or reach me by email.  Thanks, -- Steve Linderer, slinderer@gmail.com 

20 April -- Internatio nal Dark Sky Week, 20-26 April, 2014

April (all): Astronomers Without Borders Global Astronomy Month & World at Night (TWAN) 5th International Earth & Sky Photo contest
April 20: World Night in Defence of Starlight, the annual celebration of the Declaration in Defence of the Night Sky and the Right to Starlight 
April 20: Start of GLOBE at Night's April campaign
April 22: Earth Day
A page is up on the IDA website describing the Week on: http://www.darksky.org/ resources/109-international- dark-sky-week


20 Feb 2014 – astronomy talk by Dr.Bob at Lakewood Country Club breakfast meeting of the Rotary Club,

and mini-meeting of the Colorado section of IDA: Dr. Bob, Leslie Clark & Rick Angell.

Feb.11, 2014 -- From: Nancy Emerson fnemerson AT comcast.net - Feb 11

To colorado.ida AT gmail.com, Amee AT darksky.og

[update 2/20: from john@darksky.org

Thank you for contacting IDA about Chimney Rock.  My name is John Barentine and I manage the Dark Sky Places Program, having taken over for Amee Henning who left IDA last fall.

I am the IDA Chapter Leader for Santa Barbara County, CA. We recently visited the new Chimney Rock National Monument near Pagosa Springs. Based on the name, I was not sure what to expect but discovered it was an archeoastronomy site. It is located in a very dark part of Colorado and the visitor area looks like it is dark sky compliant, too. While there I talked with the volunteer in the very small visitors center and then with our volunteer tour guide. I mentioned to both of them the IDA Dark Sky Park awards and suggested they apply. They were a bit hesitant and explained that it was the volunteers who had pushed through the site's designation as a national monument in 2012. Now 18 of the volunteers are the interpretative "staff" from May-September (and beyond for schools wanting tours) so they are feeling overwhelmed with work. I learned that the change to a monument has not yet been accompanied by additional funds so the US Forest Service is operating it on a shoestring with the volunteers also continuing to do significant fundraising. As you can imagine, I am very impressed by these volunteers as well as this amazing monument. It is such a unique site that it would be a jewel in IDA's recognized parks. I am wondering if you might be able, over time, to work with them on an application. Please visit the monument's website, if you have not already visited the monument itself, to learn why I found it so unusual. (www.fs.usda.gov/detail/sanjuan/specialplaces/ and www.chimneyrockco.org).

Reply: Hello Nancy, Amee:

Thanks for the contact about Chimney Rock and its potential as a Dark Sky heritage site.  The loosely organized Colorado section indeed may have members in the Four Corners area who could personally lobby with USFS and others toward that goal.  If Amee could share with me a current membership roster, we could share your suggestion and enlist the extra help, along with what I can do from the distance of Denver to Chimney Rock.  Perhaps a conference call would be a useful next step as well.

--Dr.Bob Stencel, Denver Univ Astronomy Program and Coordinator, Colorado section IDA

New contacts:

Triana Lockaby wrote: I am in the North Denver area. There are so many street lamps and company signs, and the football stadium lit up all the time, that it seems redundant to use headlights when driving at night.

Are there any proposals to address the night lights in Denver?

Reply: Hi Triana. Metro Denver has criminally excessive amounts of badly done lighting that produces glare, trespass and skyglow. Denver city has enacted some progressive lighting regulations, but those have extensive exemptions for businesses – Denver building code details start at denvergov.org: http://www.denvergov.org/tabid/436473/Default.aspx# and


Other towns in metro Denver have assorted building code requirements – see http://www.iescu.org/lightingcodes.htm

You might call your city planning department and ask what can be done about wasteful lighting practices in your area, and see what might be next steps. Key to it all is educating anyone who will listen that we can be smarter about how we use nighttime lighting. Hope this helps.

Recent IDA newsletters, press releases, etc: Join IDA!





Solutions?  Get details at: www.darksky.org

"The sky, our common and universal heritage, is an integral part of the environment perceived by humanity. Humankind has always observed the sky either to interpret it or to understand the physical laws that govern the universe. This interest in astronomy has had profound implications for science, philosophy, religion, culture and our general conception of the universe". Proclamation of 2009 as International Year of Astronomy. UNESCO General Conference. Paris 2005.
“Persons belonging to future generations have the right to an uncontaminated and undamaged Earth, including pure skies; they are entitled to its enjoyment as the ground of human history of culture and social bonds that make each generation and individual a member of one human family.” Our premise: EXCESSIVE SKY GLOW OVER CITIES IS THE MANIFESTATION OF LESS THAN IDEAL ENGINEERING AND MANAGEMENT OF OUR ELECTRICAL AND LIGHTING RESOURCES, MOST OF WHICH CAN BE CORRECTED.Universal Declaration of Human Rights for Future Generations. La Laguna, 1994. Website: STARLIGHT: International Initiative in Defence of the Quality of the Night Sky as Mankind’s Scientific, Cultural and Environmental Rights.

0. Compilation of regional night sky photometry HERE
1. Denver City and County studying new lighting regs... details available at website DENVERGOV.ORG and search on Lighting Regulations
2. Useful links to Colorado city, county, state lighting regs:
Colorado IESNA and select link to LIGHTING CODES, near end of left column.


LIGHT POLLUTION refers to wasteful and excessive electric lighting that blocks our view of the night sky.

Light TRESPASS and GLARE refer to unwanted and harmful lighting.

During 2001, the Colorado Legislature agreed and modified state law to address these issues: SECTION 2, ARTICLE 82 OF TITLE 24, COLORADO REVISED STATUES IS AMENDED BY THE ADDITION OF A NEW PART TO READ: PART 9, OUTDOOR LIGHTING FIXTURES.

Astronomers are NOT AGAINST SAFETY, but are very worried about destruction of the night sky by lighting that shines uselessly into the sky, wasting money and depriving everyone of their cosmic birthright, not to mention causing inferior sleep and melatonin disruption. Badly aimed light also produces trespass nuisance, and disabling glare -- especially for older people.

The simplest solution also saves money: add a shield on top of new lighting, to direct all of the light toward the ground where it is needed.

Also, the use of motion sensors and timers reduce the cost of lighting to only when it is really needed.


2005 Dec: Pueblo County adopts stricter lighting regs. Link: http://www.co.pueblo.co.us/planning/planning_cases/TA%202005-003/Final%20Proposed%20Outdoor%20Lighting%20Regulation.pdf
2005 Nov: Arvada City adopts new lighting code language, www.arvada.org
2005 Sept. Regional IDA workshop, Yellowstone Nat Park
2004 Sept. 17 WORKSHOP, Frisco, Colorado:
Topics/Speakers included:
The vanishing Colorado night sky, Robert Stencel; Practical solutions for light pollution, Nancy Clanton; Crime prevention through environmental design, John Minor; Lighting Ordinance process case study, Joani Matranga & Jill Peterson

You might find local lighting codes and regs interesting: STATE and COUNTY and CITY lighting regs and proposals

House bill 1160 as introduced Colorado Legislature, Jan.2001; Rationale; and how to contact your elected state reps here in Colorado:

as well as the in-force DOUGLAS COUNTY regs:

The 1999 TEXAS LAW signed by George W. 'hissef': (& search for 1999 HB 916)
and the Texas Effective Outdoor Lighting Council

and City, County and State regs controlling lighting, NATIONALLY:

A recent composite of EARTH AT NIGHT from space (dmsp):

and how to contact your elected state reps here in Colorado:

News about growth and energy issues:
Page 1 double headlines on growth and energy, check archives for Dec.21,2000.

A few terms defined, from the Dark Sky Association homepages:

GLARE: The 8th edition of the IESNA Lighting Handbook (1993) defines glare as the sensation produced by luminance within the visual field that is sufficiently greater than the luminance to which the eyes are adapted to cause annoyance, discomfort or loss of visual performance and visibility. It stands to reason, then, that any good outdoor lighting design will minimize glare. If the light source itself is more apparent than what it is illuminating, then you have bad lighting.

Light TRESPASS is light that is distributed where it is not wanted or needed. Streetlighting, for example, should light streets and sidewalks, not shine into second floor bedroom windows or illuminate rooftops. Also known as spill light, light trespass occurs whenever light shines beyond the intended target and onto adjacent properties.

UPLIGHT is, in the truest sense of the word, wasted light. Light that goes directly up into the night sky is "lost in space" and serves no useful purpose. Uplight is the bane of astronomers and the occasional stargazer because atmospheric scattering artificially brightens the night sky, making distant celestial light sources difficult or impossible to see. Uplight often results from light fixtures which also produce glare and light trespass.

And from NEMA: FULL CUTOFF fixtures are those that allow "no light at or above a horizontal plane located at the bottom of the luminaire" (lamp plus fixture).

Contact Prof. Stencel with questions. Visit the DU Observatories: Chamberlin and Mt.Evans.
Keywords: light pollution, glare, trespass, melatonin, astronomy, astrophysics, astronomy, astrophysics, observatory, infrared, telescopes, universe, planets, stars, comets, Denver ...

For more information, visit the International Dark Sky Association homepage at www.darksky.org.