The form factor is similar to competitive 1×1 LED units. It weighs 4.18 lb. and measures 11.8” x 11.8” x 2.9”.
The fixture came with a set of barndoors, which was surprising to me. I hadn’t dealt with barndoors on a 1×1 LED unit before. It’s a nice touch. The doors are quite robust. They’ll take the abuse of production for sure.
Note that if you mount the fixture on a stand with the yoke vertical and open the doors all the way, you cannot really tilt the fixture at all. In order to get a good tilt with the barndoors open, you have to mount it with a horizontal yoke, which takes up more room and counteracts the benefits of the 1×1’s small size.
Still, I was thankful for the barndoors in a number of situations, not just for their ability to shape light but for providing finer control of the output than the dimmer alone would allow.
The 300MK features a dimmer knob, which is standard fare on LED fixtures. One nice touch here is the “thermometer” scale on the back of the fixture. Its 12 small LED indicators show you clearly where you are in the dimming range: all 12 is full bright, none is full dim. I often complain about not having a scale to show where I am on an adjustment. The Lumos takes care of it in a classy way.
Although the dimming knob has no “stops” on it—so you can turn it forever—it does have “bumps,” which tell you how many adjustments you’ve made with a slow turn. Although there are 12 LEDs in the indicator, it’s 23 bumps from 0 to 100 percent.
The “MK” in 300MK indicates the unit’s “multiple Kelvin” temperatures. The fixture can transition from 3,200° K to 5,600° K, with many stages in between. The color temperature adjustment also has a thermometer scale on it, but the scale is labeled “min,” “med” and “max.” That terminology is great for dimming but confusing when describing color temperature. What is “max” color? Is that 5,600° or 3,200°? As it turns out, 5,600° is “max.”
This knob doesn’t have final stops either, which is worse than the dimming knob not having stops because here you’re not sure which way to turn the knob. I often found myself fumbling with the color temperature control to get what I wanted.
These are, admittedly, pretty minor complaints. The fixture is well constructed and lightweight. I have no doubt that it will handle the abuses of daily production in the field. The face of the fixture has a diffusion panel in it, which eliminates the harsh exposure of LED bulbs. I had no problem lighting faces with the Lumos 300MK directly, with no additional diffusion.
Color rendition on the Lumos is excellent. I saw no significant green or magenta cast. My testing found the 5,600° K to be just slightly blue and the 3,200° K was spot on.
Perhaps my biggest issue is the smoothness of the dimming. I found several times that I was getting too little light from the fixture at its lowest dim setting, but increasing output by one bump resulted in too much light.
I found there’s about a 7x leap in brightness from the lowest dimming setting to the second lowest, which I had to counteract with the barndoors and additional diffusion. That’s a large jump. The nice thing is that you can pinch down the barndoors in some situations to reduce the output.
Pros: Robust, flexible, good design, great color rendition, good size and weight, great indicators.
Cons: Large jumps in illumination level between dimming settings, limited use of barndoors when in vertical mounting position.
Bottom Line: A good fixture that could be great if a few minor issues were addressed.