Retrofitting the street lights

Can old dropped lens cobra heads be retrofitted with flat lens glass to make them a suitable full cutoff fixture?

No, in addition to replacing the dropped lens or refractor of the fixture, the reflector inside the fixture must be replaced to properly distribute the light spread from the fixture down onto the road. Since the new flat lens fixture is relatively inexpensive compared to the cost of performing this type of customization, it is more cost-effective to replace the old fixture with a new flat lens fixture of the correct photometry.

What can cities do with their old streetlight fixtures?

The City of Calgary embarked on a massive street lighting retrofit. In an effort to be more environmentally sensitive, the fixtures were disassembled and the components – glass, steel, aluminum, etc. – were then recycled. There are a number of pictures on the Website that show streetlight components being readied for recycling. Some parts were even used for crafts. The old glass refractors can be used as pots and the ceramic arc tubes can be used for sharpening knifes. Representatives of Environmental Assessment and Liabilities at The City of Calgary presented a paper on our environmental monitoring program at the International Association of Impact Assessment Conference in Vancouver in 2004.

Wouldn’t it have been more economical to simply replace the old lights as they burned out instead of doing them all at once?

No. If we had done this project by attrition it would have taken about eight or ten years, and it would have been very hard to manage. The City replaced the lamps in the old luminaires on a 5-year cycle. With the retrofit project, the whole luminaire, including the lamp is replaced. As such, the group relamping is not being done during the retrofit, which is resulting in increased savings. In addition to reducing light pollution and glare, The City also wanted to reduce the wattage of residential streetlights in order to reduce electricity consumption. The new streetlights will save The City approximately $1.7 million a year in energy costs once the project is complete. These savings ensure that the project pays for itself. Reduced energy consumption also results in reduced emissions from gas and coal-burning generators. When the EnviroSmart Streetlights project is complete, CO2 emissions will be reduced by as much as 19,000 tons a year.

How Can We Protect the Night Sky?

You have probably moved to Custer County because of the beautiful environment–including the dark skies! The citizens here would like to preserve this environment. To that and Dark Skies (a Wet Mountain Valley volunteer organization) would like to inform you of the various issues concerning outdoor lighting to be considered when building or adding onto your home or place of business.

Good lighting does its intended job well and with minimum adverse impact to the environment. One way to accomplish good lighting is to use “fully shielded” lights, where no light is emitted above the horizontal. Shielding lights controls which areas are illuminated and prevents unnecessary light escaping upwards. But some modern lighting systems illuminate areas to a level 100 times as bright as the full moon! Too bright an area on the ground can cause Glare where people or objects in the shadows become invisible.

Careful positioning of light fixtures will also maximize the effectiveness of the illumination. Fixtures should be positioned to give adequate uniformity of the illuminated area. A few bright fixtures (or ones that are too low to the ground) can often create bright “hot spots” that make the areas in between seem dark. Even well shielded fixtures placed on tall poles on a property boundary can cast a lot of light onto neighboring properties. This “light trespass” greatly reduces and invades privacy and is difficult to resolve after the installation is complete.

In order to reduce both operating costs and save energy, use high efficiency lights such as LEDs with a color temperature of 2,700k – 3,000K, which will create a natural warm tone. Placing lights on timers so they are functioning only when necessary is also a helpful alternative to the electric eye type fixtures which are on continuously from dark to dawn, or use motion detectors on the security lights.

Good lighting means that we save energy and money, and we avoid hassles. A quality lighting job makes a “good neighbor”… and we all have a safer and more secure nighttime environment. Always remember that lighting should benefit people. Controlled, effective, efficient lighting at a home or business will enhance the beauty, while providing visibility, safety, and security. Then we ALL can continue to look up and see the Milky Way!!

By THE NEW MEXICAN

To what might be its everlasting credit, the New Mexico Legislature in 1999 enacted the Night Sky Protection Act. It recognized not just the beauty of our state’s skies, but their economic value as well.

For more than a century, travelers from the East’s smudged and glaring atmosphere have raved not only about the blue above them in the daylight, but also about the moon, the stars, the planets so bright above them at night.

New Mexico, many of them concluded, is worth many a return visit — maybe a change of residence …
But the more people who came here, the more lights they plugged in — and the harder it became to enjoy a renowned resource. The tourism industry, not to mention economic development so often spun from visits to our state, stood to take a hit if New Mexico became indistinguishable from the brightly lighted sprawl of Dallas-Forth Worth, Phoenix-Mesa or Los Angeles-San Diego.

An effort led in the House of Representatives by Democrat Rhonda King of Stanley and Republican Pauline Gubbels of Albuquerque struck a nerve with fellow legislators on both sides of the aisle. Night-sky protection gained a statutory foothold. Aimed at outdoor-lighting fixtures, the law amounted mainly to guidelines for putting hoods on bulbs, and for replacing mercury-vapor lights with effective, but less glary bulbs. Fixtures would have to be aimed below horizontal.

The law, sensibly enough, exempted lights of less than 150 watts, although the New Mexico Heritage Preservation Alliance, a major advocate of the law, campaigned for voluntary shielding of porchlights and the like. The Night Sky Protection Act was a good start — but more was, and still is, needed.

This week, the state Senate approved, 32-3, a bill providing that the state “shall enforce” the law — instead of the “may enforce” language in the original law. It’s an overdue step — and we salute Sen. John Arthur Smith of Deming for shepherding the proposal through the Senate. We urge the House to approve it, too — but something else is needed: money. The Legislature should make an appropriation to the state Construction Industries Division giving it the people it needs to review building plans and be sure that the lighting for new construction complies with the law. Had CID been given the support it needs, perhaps such recent projects as the Pojoaque fire station would have come with proper lighting.

As an official building, it should be an example for others; same for a new Motor Vehicle Division office in Deming, which went up with broadcast-glare fixtures when downward-guided ones could have been used. As more and more buildings go up around the state, they’ll sport lots of lighting fixtures. The time to regulate them is before they’re bolted on. Night-sky protection, for all its urgency, was conceded by even its most optimistic supporters to be a gradual process — but it shouldn’t be a one-step-forward, two-steps-back affair.

Building-supply manufacturers have developed all kinds of creative equipment for dimming and directing light. When old fixtures are replaced, that’s what should be used. As for new construction, ni hablar. Encourage your legislators to strengthen the Night Sky Protection Act.

Good Building Design Key to Keeping Bad Guys Away

Expensive locks didn’t help me when my office was robbed a few weeks ago, in broad daylight. The thief who made off with the computers was identified and caught through the vigilance of someone in my building who noted a suspicious character lurking about. This experience points to the importance of natural surveillance for crime prevention, one of the principles of CPTED (Crime Prevention Through Environmental Design). CPTED, an approach that originated in the 1960s, is based on a theory that the proper design and effective use of the built environment can reduce crime and the fear of crime. Research into criminal behavior shows the decision to commit a crime or not is heavily influenced by cues about perceived risk of being caught. CPTED strategies increase a criminal’s perceived risk of detection using three main strategies: Natural surveillance, natural access control and natural territorial reinforcement. Natural surveillance, sometimes called “eyes on the street,” is achieved by designing the placement of physical features, activities and people in ways that provide maximum visibility and foster positive social interaction among legitimate users of private and public space. Potential offenders feel increased scrutiny and limitations on their escape routes. Examples include placing windows in active rooms — such as kitchens, overlooking sidewalks and parking lots — leaving window shades open or using the shortest, least sight-limiting fence appropriate for the situation. Lighting design is an important element of natural surveillance. Poorly placed lights create blind spots for potential observers and miss critical areas. Although some areas need bright lighting, too-bright security lighting creates blinding glare and deep shadows, hindering the view for potential observers. Bright lighting can highlight people as targets. Lower-intensity lighting often requires more fixtures, but is generally much more energy efficient. Natural access control limits the opportunity to commit crimes by establishing a clear difference between public and private space. Some ways it can be achieved include things like planting low, thorny bushes beneath ground level windows to deter people from looking in. In most cases, fencing should not obscure views and should make it easy for neighbors to connect, building a sense of social interaction. The closer the neighbors are, the more they look out for each other. Another key measure of CPTED is territorial reinforcement, which employs such design elements as sidewalks, landscaping and porches to help distinguish between public and private areas and help users exhibit signs of ownership that give “hands off” messages to would-be offenders. Physical design can create or extend a sphere of territorial influence that potential offenders can perceive. For example, low walls, landscape and paving patterns can clearly define the space around a unit entry as belonging to the residents of the unit. Territorial reinforcement measures make the legitimate user feel safe and make the potential offender aware of a substantial risk of getting caught. It creates a sense of ownership, since owners have a vested interest in protecting their space. The sense of owned space creates an environment where “strangers” or “intruders” stand out and are more easily identified. Some ways of achieving this include building design and landscaping that communicate an alert and active presence occupying the space. Placing amenities such as seating in common areas helps to attract larger numbers of desired users. Similarly, scheduling activities in common areas increases positive uses, attracts more people and increases the perception that these areas are controlled. Research also indicates that outdoor residential spaces with more trees are seen as significantly more attractive, safer and more likely to be used than similar spaces without trees. On the other hand, a fortress mentality with measures like putting up heavy-duty cyclone fencing and razor wire actually communicate the absence of a physical presence and suggests lower risk of being detected. Good care and maintenance are also important, as deterioration indicates less concern and control by the intended users of a site and a greater tolerance of disorder. CPTED takes more upfront effort but usually involves lower long-term costs, lower losses due to crime and higher quality of life.

How to Select the Best Telescope for You

There is no one best choice that fits everyone. There are 100s  of possible choices, the issue is now to go about deciding. The best telescope for you is the telescope that you will use most often.

Key Issues:

  • What do you want to look at? How do you decide?
  • Astrophotograpy planned? Terrestrial use? Solar use?
  • What is your budget? Just how serious are you?
  • Does it need to be portable? Fit in an RV? In a car’s trunk? Even just move out from a garage.
  • Ease of set-up an issue?
  • The Magnification Scam! If the box or ad promotes how much it magnifies, it’s probably junk.
  • Aperture Rules! In general, the larger the aperture (main lens or mirror) the more you can see.
  • Mounting as important as optics

Types of Telescopes:

  • Refractor
  • Reflector
  • Catadioptric or SCT
  • GoTo?
  • Binoculars

Accessories are needed, too:

  • Eyepieces
  • Filters
  • Barlows
  • Observing Chair
  • Flashlight
  • Star Charts
  • Storage case

Telescope Design Issues:

Refractor—Advantages

  • Little or no maintenance and is easy to use. No cool-down time.
  • Reliable simple design.
  • Excellent for lunar, planetary or binary star.
  • Good for terrestrial viewing.
  • High contrast images due to its clear aperture (no central obstruction).
  • Sealed optical tube.
  • Objective is permanently mounted and aligned.

Refractor—Disadvantages

  • Usually more expensive per inch of aperture than Newtonians or Catadioptrics.
  • Heavier, longer and bulkier than equivalent aperture Newtonians or Catadioptrics.
  • The cost and bulk factors usually limit the maximum size to smaller apertures.
  • Less suited for observation of deep sky objects because of aperture limitations.
  • Poor reputation due to low quality imported toy telescopes

Reflector—Advantages

  • Lowest cost per inch of aperture.
  • Reasonably compact and portable up to focal lengths of 1000mm 40”.
  • Excellent for faint deep sky objects.
  • Reasonably good for lunar and planetary work.
  • Good for deep sky astrophotography if properly mounted.
  • Low in optical aberrations and deliver very bright images.

Reflector—Disadvantages

  • Requires regular alignment (collimation).
  • The open tube could mean more complicated cleaning compared to other designs.
  • Generally not suited for terrestrial applications.
  • Slight light loss due to secondary (diagonal) obstruction when compared with refractors.

Catadioptrics—Advantages

  • Best all-around, all-purpose telescope design. Most are extremely compact and portable.
  • Good for deep sky observing or astrophotography with CCDs.
  • Very good for lunar, planetary observing.
  • Good for terrestrial viewing or photography.
  • Closed tube design reduces image degrading air currents.
  • Easy to use.
  • Durable and virtually maintenance free.
  • Large apertures at reasonable prices.
  • Best near-focus capability of any type telescope

Catadioptrics—Disadvantages

  • More expensive than Newtonians of equal aperture.
  • It is not what people expect a telescope to look like.
  • Slight light loss due to secondary mirror obstruction compared to refractors.
  • May suffer from image shift since the primary mirror is usually moved for focusing.

General Recommendations—

  • Child [<$50]: cheap binoculars and basic star chart
  • Teenager [$250]: better binoculars and mount or basic Dob; and observing book
  • Adult w/limited budget [$500]: good binoculars, mounting, or 80mm refractor, extra accessories; and observing guides
  • Adult w/medium budget [$1-2,000]: mid-size Dob or CAT, w/o GoTo but can be added; and star maps & observing guides
  • Adult/big budget [$5,000]: large Dob or CAT on GoTo mount; and computer-aided star charts
  • Adult/RV: small CAT or 80mm refractor on basic tripod mount; and observing guides
  • Adult/unlimited budget: huge Dob or large CAT on Paramount mounting, CCD, etc. in an observatory with remote computer operation