Installed by Rainbow Garden Nursery of Glendora, CA
Lamp Charts: Friend or Foe?
Amending relationships between lighting designers and lamp charts one day at a time
Lamp charts...What are they good for anyway? Although lamp charts can be extremely difficult to read when first getting to know them, we encourage you to try to add them to your arsenal of tools. They can make your life easier in the long run by not having to guess on lamps and light intensity when designing.
At Nightscaping®, one of our design philosophies is to have between .5 and 2.5 footcandles of light distributed throughout the landscape. This number increases to between 3 and 5 footcandles in public spaces. Some city regulations will require a minimum amount of footcandles on walkways, handicap ramps, and parking lots. Requirements like these can easily be met by reading your lamp charts properly.
So what does this mean and how do we achieve it? Light is measured in footcandles. A footcandle is the amount of light falling on a 1' x1' square surface 1' away from a candle.
This doesn't mean much to anyone without incorporating a way to reference it in our daily observations. The spectrum of light we see on a daily basis ranges from between 10,000 footcandles in full sun to 1/100 (or .01) of a footcandle in full moonlight. Even darker would be full starlight, with no moon present, at 1/10000 (or .0001) of a footcandle. Below you can see the range of footcandles that fall in between.
Click to enlarge
When designing, think about your lamp chart as a tool to help achieve your optimum goal. Here is how I like to do it:
- When lighting a Crape Myrtle tree that is 20 feet tall and has a canopy that is 15 feet wide, I first decide that I like the color temperature of the MR16 lamp. Next I go to my faithful lamp chart and discover that the 20 watt lamp with a 42 Degree BAB lamp will fulfill all of my needs. (Please refer to previous Nightscaping® Newsletter for information on the color and intensity of different lamps.)
Looking at the left-hand side of the chart, at 14'-20' away from the fixture, the footcandle reading will be between 2.7 and 1.3. This fits perfectly within the residential footcandle range of .5 and 2.5. Since this tree is to be a focal point, I want the footcandle reading higher up in the range, which it is. Also, at 20' away from the fixture, the beam spread will be 15'4" wide, which is the exact same width as the Crape Myrtle that is being lit.
I also want to light a Cypress Tree that is 40 feet tall with a diameter of approximately 6 feet. - When I look over my lamp charts, I find that the 20 watt 12° EZX lamp will give me a 4'6" width at 20'. By doubling the distance and doubling the width of the beam, I know that at 40' the beam will be approximately 9' (4'6" x 2). I can find the footcandle reading at 40' by using the following formula: Candle Power / Distance Squared. The Candle Power for an LO2012 is 3,600 which I found from looking it up on a lamp chart. Following the formula I am able to find the footcandles at 40': 3,600 divided by 40x40 = 2.25 foot candles. I think this lamp is perfect for my situation since the top of the Cypress Tree tree will be receiving 2.25 footcandles.
Lets look at one more lamp chart and see what it can do for your lighting design.
This photometrics chart is for pathlights which put out a ring of light in every direction, rather than the directional beam of light in the previous two examples. As you get further away from the fixture the footcandles are reducing. At 2' away, in every direction, the footcandle reading is 2.81. At 8' away, the footcandle reading is .18. If this isn't bright enough, look through the photometrics charts for a lamp which will better suit your needs.
I like to suggest that lighting designers pick their lamp out before picking out the fixture in order to get the specific effect they desire.
Get friendly with our Lamp Charts
Get warm and cozy with our Photometrics Charts: Par 36, MR-16, MR-11, MR-8, Bayonet, Wedge Base, Xenon
By understanding how to read lamp charts, and knowing what your target range of light output is, you can gain more control over your lighting designs with the advantage of saving time and money.
Installed by Rainbow Garden Nursery of Glendora, CA
Contractor of the Week, Mike and Carol Downard
Mike and Carol Downard are the owners of Rainbow Garden Nursery located in Glendora.
Mike and Carol have been in business since 1978 and are owners of a nursery and a successful landscape installation company. They have a group of dedicated employees doing total landscape installations including great landscape lighting. Their motto is "Our staff will help you enhance your property and enrich your daily life".
They service the Glendora, San Dimas and Covina cities and beyond.
They originally started using aluminum and steel fixtures from Nightscaping® and have graduated to copper and brass for many of their new installs. They have three girls and are very involved in their church. The attached photos are from a Townhome complex that was installed in 2006.
We are proud to have them as dedicated Nightscaping® contractors.
They originally started using aluminum and steel fixtures from Nightscaping® and have graduated to copper and brass for many of their new installs. They have three girls and are very involved in their church. The attached photos are from a Townhome complex that was installed in 2006.
We are proud to have them as dedicated Nightscaping® contractors.
Installed by Rainbow Garden Nursery of Glendora, CA
A Few Nightscaping® Fixtures That Can Be Spec'd In Brass...
Brickliter: Use the Nightscaping® brand Brickliter wherever a small recessed light is needed. Designed to be the size of a standard brick, this fixture can be installed where other fixtures might be too conspicuous in the landscape. It is ideal as a hidden source of safety light.
Postliter: Light decks and docks with the Nightscaping® brand Postliter. Built specifically for this type of construction, the Postliter fits perfectly onto finished 4"x4" (3-5/8"x3-5/8") posts. The low-profile design blends seamlessly with construction as the fixture lends safety and traverse lighting to steps, walkways, decks and docks.
1705 E. Colton Avenue, Redlands CA 92374
ph:909-794-2121 toll free:800-544-4840 fax:909-794-7292 email:info@nightscaping.com