How much can you control beam spread with the glare shield? I'm wondering if you can reduce a 40deg spread significantly by adjusting the glare shield.
There’s not really a straightforward answer to your question. What are you lighting? You can narrow or widen the light beam by raising or lowering the glare guard or cowl but the impact of adjusting the guard will depend on the length of the cowl, the lamp’s brightness and the surface onto which the light is being projected. By the way, while I was thinking about your question, I discovered VOLT has recently started selling an MR16 with an adjustable beam angle. I’m looking forward to trying it out. https://www.voltlighting.com/adjustable-beam-angle-led-mr16-bulb
Nathan: Meso is right, trying the narrow the beam the way you want would be highly dependent on the physical dimensions of the glare guard. A photography snoot could work. I installed some 1.5 inch long, 1.5 inch diameter snoots on my garage door puck lights to narrow the beam from 120 degrees to 40 degrees, but trying to find just the right snoot for your application would be an internet search nightmare. Meso is right (again), it would be easier just replacing the bulb.
