The Light Pollution Awareness Web site

Effectively Shielding Outdoor Lighting

Thank you for visiting this web site published to help you improve the outdoor lighting quality on your property and in your community.   Obtrusive outdoor lighting that shines visible glare severely diminishes everyone's ability to see well in the nighttime environment.   We always shield lights indoors to eliminate glare, don't we?   Have you ever wondered why we put shades on the lamps in our homes?   We do this because generations ago when electricity was first made available to society our ancestors rapidly learned they could always see much better and be more comfortable when the glare from their lights was kept under control and hidden from view.

Visible glare imposes serious negative effects on our safety and quality of life.   It is especially dangerous for the elderly and those who have even the slightest visual impairments. Well executed outdoor lighting always shields the source of glaring illumination, making it discrete and hidden from view so only the illuminated area is visible from a distance.   Some people refer to this kind of lighting as being neighbor friendly because it is considerate of others both on and beyond the property where the fixtures are installed.   One additional benefit is if outdoor lighting is eye friendly it will usually be sky friendly, too.

Most of us have not noticed the dwindling view of the stars because Light Pollution caused by uncontrolled glare and uplighting crept up on us so slowly, one obtrusive light after another over the past several decades.   Most children born today will never know the splendor of a dark star filled night sky and that alone is tragic.   My own daughter never saw the Milky Way until she was 14 years old and it is our stellar neighborhood in the Universe!   We carelessly pump so much stray light into the night sky today we cannot even see our stellar back yard any more!   Researchers recently indicated that 90% of Americans now live in areas with varying stages of Light Pollution where 2/3 of the population can no longer see the Milky Way.

Not more than a decade ago one could travel to the country and experience a pristine dark night sky with jet black horizons, but not any more in most areas.   Skyglow on the horizon has invaded many of the most rural and remote areas.   This happened because the intensity of lighting available today is more powerful than it has ever been before, all in the interest of achieving greater energy efficiency.   The quandary is no light can truly be considered energy efficient if it is distributing more illumination than is needed for the task. If light spills beyond property boundaries where a fixture is installed, or if it is shining into people's eyes or into the night sky it cannot be considered an energy efficient application. Some professional lighting design software can now calculate the Upward Wasted Light Ratio (UWLR) to help designers recognize and take measures to minimize this needless waste.

You can help fix this problem on your own property.   Simple solutions to tame glare and light trespass are found in the page below.   Creating effective and attractive shielding is not only fun, it is also greatly rewarding in many ways.   You may soon notice other neighbors shielding their own outdoor lighting after they notice how attractive your property looks at night.   Once you become aware of Light Pollution issues you may notice good lighting almost immediately.   In fact, it is difficult not to notice and appreciate good lighting when we learn to notice it.   Make a note of where the good lighting installations are in your community so you can point them out to others and explain the benefits in ways that relate to them.   Doing this will help to raise others' awareness about the importance of always using good lighting.   It will help us all save energy and natural resources by learning how to only use as much light as we need for the tasks at hand.

To achieve a 'feeling of safety' research indicates most people only need 0.1 footcandle of illuminance uniformly distributed across the task area, but many applications today apply 1000 times that much light with the hopes of attract more consumers to gas stations and outdoor display lots like vehicle dealerships. Can owners of these establishments apply much less light and still enjoy the benefits of healthy sales? The IESNA RP-33-99 voluntary lighting standard for outdoor environments suggests we can if designers pay close attention to mitigating the harmful effects of visible glare through the application of effective shielding and careful fixture aiming.

This seemingly small effort of shielding lights on your property helps us be more considerate of ourselves, our neighbors, and everyone else who passes by our property at night.   Until the recent development of more powerful energy-efficient lighting products this has not been a factor that gets considered when new lights are installed. Without a keen level of awareness people may not realize how severe the negative impacts unshielded lights can have on ourselves and others' ability to see well outdoors at night.   After adding effective shields you may be able to reduce lamp wattage by 30% or more and perceive no loss of visual performance, too!   This often becomes possible when glare is effectively controlled because the eye is able to adapt to the lower light level. Our vision always adapts to the brightest object in the field of view and the objective of good lighting is to illuminate what we need to see without drawing attention to the source of light. The Laws of Physics demand the fixtures will always be brighter than anything they illuminate, so help the eye work as nature intended by shielding it to make the source of light be as discrete from view as possible.


For advice on properly applying floodlights visit the CfDS web site at:

Examples Showing the Benefits of Good Shielding

Hubbell Skycap turns glaring fixtures into full cutoff fixtures!
Click to see full image

Roadway and Area Lighting   The benefits of shielding outdoor lighting are immediately apparent when we see good examples.   Some very good examples of neighbor friendly lighting may exist in your community.   The image at the bottom left shows the vast improvement that a Hubbell Skycap can provide for roadway lighting.   These photos were taken from the second-story bedroom window of a home in Ames, Iowa.   Photos ©David Oesper of Outdoor Lighting Associates.

The modified Hubbell Skycap is available from the following company:

        Outdoor Lighting Associates, Inc.
        1208 Wilson Ave.
        Ames, Iowa 50010-5426
        Phone & Fax: (515) 233-0117

Click the image to visit Outdoor Lighting Associates, Inc., today!
Catalog #SCMD
Outdoor Lighting Associates recently introduced a new fully shielded product for the Regent dusk to dawn fixture commonly sold at Lowes, Home Depot, and some hardware stores.  They have also become a distributor for the RAB "Neighbor Friendly" lighting products. Visit their web site today and inquire about these exciting new products!

Shielding Existing Outdoor Lighting
A little sheet metal can improve contiditons enormously!

Click the image to see a larger version

Click Here to view before and after photographs to see how effective this easy to install economical solution worked for a commercial lighting system located at Hoyts Cinema in Branford, Connecticut.   Photos ©Bob Crelin

Standard Shielding Products from Manufacturers


Click image for larger view

Residential Lighting   This example shows how easy and inexpensive it can be to proactively improve the outdoor lighting on your property.   Notice how much brighter the stairs and ground appear on the right.   This occurred because 30% more illuminance reaches these areas simply by adding a shield!   The ground illuminance measured 1.0 footcandles with a bare bulb and 1.3 footcandles after shielding was applied.   This is a net gain of 30%, which is the typical result of what one can expect after adding proper shielding.   Effectively, the 60-watt lamp can now be swapped for a 40-watt lamp and still get 1.0 footcandles of illuminance on the ground with no loss in visual performance.   The resulting illuminance reading is 50% higher than the minimum recommended illuminance specified in the IESNA RP-33-99 "Lighting for Exterior Environments".


Click the image for a larger view

The shield has been painted to match the color of the home, and as a result, it is hardly noticeable.  At night when traveling by this home there is no glare and only the illuminated area is visible.   The exposure time was identical for both of these photos.   Film was Kodak ASA-400 35 mm print variety and exposure time for each photo was 45 seconds using a 50 mm macro lens set at f/2.4.

This shield took less than 5 minutes to create and it cost absolutely nothing.   The shield was created from a one-quart Dole pineapple juice can!   When first fitted, the efficiency of this luminaire was improved so much that it created too much brightness.   The interior of the shield had to be painted flat black to tame the glare!


Manufacturers Come to the Call For Eye Friendly Lighting!

Obtrusive Outdoor Lighting Responsible Outdoor Lighting

The deleterious affects of glare can seriously impair drivers' ability to see people walking and avoid hazards along the roadway or within parking lots!   Have you ever experienced the effects of veiling luminance before?   That is what happens when too much light prevents your ability to see properly.   The effects of veiling luminance are hiding the pedestrians in the above photo on the left.

More is not better when speaking of outdoor lighting!   If you can see the source of the light it is an obtrusive light that is actually causing more harm than good to the surrounding area!   The above photo on the right is how responsibly applied outdoor lighting appears.   It is properly shielded and provides a soft glow without hammering the eyes with the obtrusive and deleterious effects of glare.

Good shielding that prevents light from shining horizontally into the eyes is what helps to improve safety and security.   Shielded lighting also allows lowering wattage of lamps to save energy because it redirects the light only to where it is needed.   Shielded low wattage lighting provides a win-win solution to many problems attributed to obtrusive eye abuse that is caused by poorly aimed and unshielded lighting.

The two photos above are reproduced on this web site with the written permission of Richard Barma, Chief Executive Officer of RAB Lighting, Inc.. Visit the RAB Lighting web site to discover other products that can help you reduce the impact on your property. RAB Lighting


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Historically, in the arena of residential and light commercial outdoor lighting, there has been a large gap with the availability of high quality, well shielded fixtures.   Most have bare bulbs in plain view with no shielding whatsoever.   At night, this causes the very bright source of light to send glare directly into our eyes, which in turn causes a tremendous loss of visual acuity.   Glare overwrites the images on our retina that naturally results from light reflecting off of illuminated objects.   This visible glare makes items appear much darker and can also cause deep dark shadows.   When the glare is controlled by good shielding we can use much lower wattage lamps to light our properties, whether it be used for hospitality lighting at our homes or for security lighting at our place of business.   The GlareBuster serves this need well and fills a void that has existed for over a century in the history of outdoor lighting.

You can order the Glarebuster directly from the Affordable Lighting web site, or better yet, stop into the store for a visit to see it first hand. Tell them you learned about their product from the Light Pollution Awareness Web site and be sure to tell them that Cliff Haas sent you.

      Affordable Lighting
      727 Boston Post Road
      Guilford, CT 06437
      Ph# 203-458-7116 Fx# 203-458-2209
      Call toll free: 1-800-548-8714
  Orders can be placed by email:


NEMA head with acrylic lens      Shielding Dusk-to-dawn Security Lighting       NEMA head with acrylic lens

Click image for larger view

The glare and light trespass caused by dusk to dawn lighting of this kind is unbearable and very inconsiderate.   This luminaire is commonly found in all hardware and home improvement stores.   The Hubbell Skycap will fit some of these luminaires but no manufacturer makes shielding for the Regent variety that uses a fiberglass reinforced plastic housing.

For barn lights with NEMA style housings that the Hubbell Skycap will not fit, use 8" wide aluminum roof flashing to create an effective shield.   Two 5" stainless steel hose clamps work well to attach it.   Roof flashing comes in 50 yard roll for around $9 (US) and is generally available from most hardware and home improvement stores.   It can be cut easily with tin snips or heavy scissors.   One roll of flashing is enough material to shield all of the lighting on most residential properties.

How to Make This Shield

Measure the outside diameter of the luminaire housing where the plastic lens (refractor) attaches.   To establish the circumference around that diameter use the following formula OR wrap your measuring tape around the circumference and measure it directly.   For this project exact precision is not required.   The objective is to assure you have enough material to wrap the opaque shield completely around the luminaire with an overlap of at least one inch.

The Formula
      D = diameter
      R = radius = D/2
      C = circumference
      π = 3.1416

The formula to establish circumference is:

C = 2πR

Say for instance the luminaire has a 9" diameter, the formula would be applied as follows:

R = 9/2 = 4.5
C = 2 x 3.1416 x 4.5

Therefore, the circumference = 28.2743" or 28-1/4" respectively.

Add 1 to 2 inches to this number before you cut the material.

Cut the flashing 1 to 2 inches longer than the total circumference of the housing. This allows an overlap of the material and it will also make a more stable shield.   Most of these lights require around 30 inches of flashing or so, but each housing is slightly different in size depending on the manufacturer.   Measure twice and cut once.

Connect two 5" hose clamps together by unscrewing each one until the worm screw is free of the band, then place the band from one clamp into the worm screw of the other hose clamp and tighten each screw about 3 turns to secure them together into a single 10" diameter clamp.   Place the clamp around the luminaire housing.   Tighten it until around 1/8" gap appears between the clamp and the housing.   This will make it much easier to tighten the clamps after the flashing is put in place.   Large stainless steel hose clamps are available in the plumbing section of any well stocked hardware or home improvement store.

Form the shielding around the luminaire housing, then remove it and and roll it about an inch or two tighter than the diameter of the housing.   Metal always retains a memory and will try to return to its original shape after bending unless it is bent slightly smaller than its final shape.   This step will make the shield much easier to attach.

Carefully place the shielding between the luminaire housing and the clamp.   If possible, get a helper to hold it in place while tightening the screws on the clamps.   Tighten the clamps until the shield is held firmly in place.   CAUTION: Do not over tighten the hose clamps because they can crush or crack the fiberglass impregnated plastic of the luminaire housing.   A snug fit will prevent the shield from blowing off in the wind and it will not damage the housing if it is tightened with the correct tension.   Remove the plastic refractor lens by twisting it gently to one side or the other using a radial motion.   Refer to the photo below to see the final assembly in place.


Click for full size

A close-up of the completed shield appears at the left.   A small tab was cut and bent up by 1/2" x 1/4" on the bottom to assure the shield would remain stable in heavy winds, ice, and snow.   A 30% gain in ground illuminance was gained by removing the clear refracting lens and replacing it with an opaque aluminum shield.   Total cost was $6 and all light now remains on the property much to the delight of the owner and their abutting neighbors.

Many thanks to Mr. Paul Merchant, Jr. of Dartmouth University for his courtesy in notifying me about a previous error that was listed in the project description above!   Indeed measuring the *circumference* of the luminaire was intended to create this shield, hence, the Geometric formula was included for better clarity.

Please write back with your comments indicating how this shield works for your obtrusive lighting reform projects!   If you have other shielding ideas that have worked well please let us know so we can detail them here! Your efforts may help hundreds of other people achieve successful solutions to glaring lights in their areas.   You may contact us by sending email to:

Petroleum Retailer Canopy Shielding

Modern petroleum retailer canopy lighting has to be one of the most obtrusive and obnoxious outdoor lighting applications in existence today.   Based on the false premise of safety and security petroleum retailers argue with town officials they need enormous amounts of light to assure public safety for their customers.   While adequate amounts of light does indeed provide the benefits of improved safety by allowing us to see better, providing enormous amounts of light to dark adapted eyes of drivers is counter-productive and can pose serious safety concerns.   No outdoor application should exceed a 10:1 brightness ratio for adjacent areas!   This means that if the road is lit to 0.6 footcandles no site directly adjacent to the road should be lit to more than 6 footcandles to assure the safest lighting conditions.

The recent trend in canopy lighting has gone over the top by installing obnoxiously bright and unshielded drop lens fixtures that shine enormous amounts of glare and light trespass.   This needless assault on our senses brings unsafe conditions into the community and unfairly imposes enormous negative impacts on surrounding property owners.   Town officials can, and should, insist these glaring luminaires be fully shielded from view beyond the property lines, but often they feel powerless with what can be done to mitigate the problem.   The good news is that an inexpensive and very effective solution is available! By simply ringing each of the new glaring luminaires with a sheet metal shield the problems causing light trespass and glare into the adjacent roadway can be mitigated entirely at very little fiscal impact to the owner of the facility.

See the graphic below to learn how to shield these fixtures effectively.   Painting the exterior portion of the shield to match the canopy gives an attractive factory finished appearance and painting the interior area of the with a shield matte black finish helps further mitigate the harmful effects of glare and light trespass.   The matte black finish on the interior surface of the shield provides even light distribution without propagating glare.   The shield should extend at least 1 inch below the lowest part of the refracting lens for the best results.


Click the image for a larger view

Shielding Plans and Diagrams

See plans below for creating a PAR floodlight shield

  • Click Here for PAR Floodlight Shield Plans   The PAR (Parabolic Aluminized Reflector) floodlight is one of the most common types of residential and light commercial outdoor lighting.   It is inexpensive and available in standard incandescent and quartz varieties.   This floodlight screws into a standard A19 outdoor lamp socket and can be very obtrusive over great distances if it is not tamed properly with a good shield.   The problem is no shielding for this type of light has ever been available until now.

  • Commercial Security Lighting Energy Saver - Timer circuit fitted with a photocell switch that any electrician can install.   This device allows using a timer to turn lights off at a specific time and uses a photo-sensitive switch to turn lights on when conditions require.   Save time, trouble, and extra expense of resetting timers during season and time changes. Easy to install, economical to operate, and can pay for itself in savings within the first year! View Plans - requires Autodesk Whip browser Plug in. (see link directly below)

  • Download the Autodesk Whip® Internet Browser Plug in   This plug-in will allow you to view and print AutoCAD drawings that have been published to the Web.   Has layer display, zoom and pan controls, too!   This plug-in is a must have for any designer, architect, or engineer.


As you see, economical shielding solutions are indeed possible!   There is absolutely no logical nor economical reason to allow offensive and obtrusive luminaires that inconsiderately shine glare to remain unaddressed in your communities!   Effective and economical light fixture shields can be created from inexpensive and readily available materials.   Please visit the page below to see shielding designs for a sag lens semi-cutoff fixture and a non-cutoff wallpack luminaire that are very easy and inexpensive to make and install.   Floodlighting is easily shielded also!   See the IDA Information Sheet #159 listed below to learn how easily it can be done.

*** New Product ***   An easy to install snap-on PAR-38 bulb shield that helps to control light spill from these ubiquitous light polluting bare bulbs found on most people's homes.   Would make a nice gift for your neighbor to get their light out of your bedroom.   Comes in gray, off-white, white, and bronze.   Developed by a member of IDA.   Click Here to receive more information, or visit

The quality of this product is excellent and it is very easy to install.   This shield provides an ideal solution for the home or small business owner.   NOTE: For shielding flagpole lighting this shield is superior to the PAR shielding plans mentioned above due to its 360 degree coverage that will reduce off-axis glare that is visible to drivers and pedestrians along the roadway.   Please click on the image below to inquire about shield ordering information. (Note: Junction box, bulb, and fixture not included)

Click image to send an inquiry message...


Email your questions or suggestions for shielding other outdoor luminaires.   Maybe we can help develop an effective design for your application.


***IMPORTANT LIGHTING FACT ***   More is not better when speaking of outdoor lighting!   The quality of light is far more important than the quantity.   If you can see the source of the light it is very likely to be obtrusive lighting that is actually causing more harm than good to the surrounding area and your visual performance!   Good shielding and properly adjusted luminaires that prevent light from shining horizontally into the eyes is what helps to improve both safety and security.   Shielded lighting also often allows lowering the wattage of lamps to save energy because it redirects the light to only to where it is needed.   When glare enters the equation, it generally is necessary to introduce much more light than needed for the task at hand.   This is done by many designers to overcome the negative veiling visual effects by raising background luminance, but during that process, much more energy is wasted needlessly and deep shadows appearing in perimeter areas are most often the result.   Well shielded low wattage lighting provides a win-win solution to many problems attributed to obtrusive eye abuse that is caused primarily by poorly aimed and unshielded outdoor lighting.


Camper's Relief -- Learn How to Make an Eye Friendly Lantern


Ever wish you had a fully shielded camping lantern?
Learn how easy it is to
make one click here!

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