LOST IN THE SHADOWS
For me, using LEDs as task lighting is still a developing technology. I am very happy with the lumen output that we are starting to see now, along with the color quality. I personally lean towards a warmer color tone that is close to that of incandescent (2700° Kelvin), but many others do prefer the slightly cooler color temperature like that of halogen (3000° Kelvin). Still others that are doing fine detail work, such as jewelry making, like to have a color temperature close to that of daylight (5000° Kelvin).
Where I am seeing room for improvement is how to deal with the creation of multiple shadowing when more than one LED source is used in a task light. Those fixtures on the market with a single source LED act like a single source incandescent or fluorescent. One source equals one shadow, which is what we have all grown up with what we are used to seeing. But a single source LED may not provide enough illumination for many people. When multiple light sources are used, as we are seeing in the LED task lights that are coming onto the market, you get a shadow image for each light source. The more individual LED diodes you have in a fixture the more shadowing you get as well. When reading a book or a magazine this really isn’t an issue, but if your hand, pen or pencil comes in between the light source and the work surface it can have a lot of disconcerting shadowing with which to contend.
Although I am not lighting fixture designer, per se, I think of myself as an informed consumer who is constantly testing what is available out there on the market. My suggestion to the task light designers is that when multiple LED sources are used then some sort of diffusion material, in the form of a lens, will help ameliorate the problem. As individual LED sources become stronger and only one source is used then shadowing no longer is an issue.
Many manufacturers of recessed LED fixtures have seen that that this multiple shadowing was an issue and have produced fixtures with an integral diffusion lens. It would be a good idea if the manufacturers of LED task lights would take a look at what the recessed LED fixture manufacturers are doing and see how they can incorporate the addition of a diffusion material into their products.
I still am a very strong advocate of using LED sources for task lighting. I would just like to see the next step in refinement; so that when people make the investment they are getting something that they can live happily with for the next 16 or 17 years. Since LEDs last for so darn long I want to make sure that my love will last.
Randall Whitehead is a frequent contributor to Green Architecture Notes.