A Look Inside the Fresnel Design Process
Today we’re interviewing Jeff Lee, Ph.D. and head of product development at Fiilex. In this segment, the first in a series of four, Jeff provides an overview of Fiilex’s Fresnel design process, and how it differs from standard industry practices.
When it comes to Fresnels, what does the industry generally do, and what does Fiilex do differently?
Traditionally what most lighting companies do when they’re making Fresnel fixtures is they buy off the shelf. There are a lot of Fresnel manufacturers out there, essentially it’s molding glass or plastics, and they serve generally the same purpose, which is to take light and redirect it in a more focused pattern. Our approach is different because it’s not that other fresnels on the market won’t work for our source, it’s that they don’t work as well and to our standards. And so because of that we design our fresnels from scratch. using computer simulations and then custom moldings.
Jeff Lee, Ph.D.
Very few companies out there are doing custom molded fresnels, mainly because they wouldn’t know how to design a different fresnel anyway. There are a lot of subtle tweaks that you have to do to the fresnel to get maximum performance. Typically if you’re using off the shelf fresnels you’re not gonna be able to get as much of a zoom range, going from flood to spot. And also throughout that range you’ll occasionally get issues of having sort of hotspots in the middle, or even—in some cases—like a bright ring of fringing around the outsides.
So you’re customizing everything in-house specifically for your LEDs?
We’re custom designing our fresnels to work in conjunction with our Dense Matrix LED array. The LED comes first. That’s where we start. We start with a light source. And then we design the fresnel around that. We do iterate between the two. Based on the fresnel sometimes we’re able to make small adjustments to the way we arrange the chips on the LED as well.
In our computer simulations what we’re trying to do is plot the trajectory of every little photon that’s emitted from our source as it travels through space. Whether or not it’s reflected off a reflector, or it’s refracted from glass. And ultimately the combination or the mixture of all those photons is what gives us our light spot.
In the end, what’s the benefit to the user for all this custom work?
After all this effort in designing the fresnels – optimizing the array, what we end up getting is a really wide zoom range that goes from flood all the way to spot, and more importantly it’s – throughout that entire range our spot is well-defined. It’s smooth. The color mixing is good everywhere in that range.
This has been part one of our series on the tech behind Fiilex. Stay tuned for future installments!