Hey everyone,

I've been researching PBM devices for a while now and I'm seriously considering pulling the trigger on a Vielight Neuro. The science behind intranasal stimulation targeting the cribriform plate looks solid, and Vielight seems to be the only company with proper clinical trials behind them.

That said, $5k is a LOT of money, and I want to make sure the intranasal diode actually produces a well-collimated beam — not just a diffuse red glow like a cheap Amazon LED. Vielight markets their Vie-LED as having "laser-like irradiance," but I haven't been able to find any independent measurements of the actual beam profile anywhere online.

If you own a Vielight with the intranasal clip, could you do me a huge favor and take a quick beam profile photo? It would take about 5 minutes and would help me (and probably a lot of other people considering this device) make an informed purchase decision.

Here's a simple step-by-step protocol I put together. You don't need any special equipment - just a phone camera, a ruler/tape measure, a piece of white paper, and a dark room.

📐 How to Measure the Beam Angle (5-minute test)

What you need:

• Your Vielight with intranasal applicator detached from the nose clip
• A piece of plain white printer paper (matte, not glossy)
• A ruler or tape measure (cm)
• Your phone camera
• A dark room (bathroom with lights off works great)

Important note about 810nm light: The Vielight intranasal uses 810nm near-infrared. This is barely visible to the naked eye as a very faint deep red cherry glow - you might think it's not even on! But your phone camera can see it perfectly. Just point your phone at the lit applicator and you'll see a bright spot on screen.

Step-by-step:

STEP 1 - Set up the projection surface

Tape or lay a sheet of white paper flat on a table. Place your ruler on the paper so you can see centimeter markings in the photo later. The ruler should lie flat on the paper, running horizontally through where the light spot will land. This gives us a built-in scale reference in every photo.

  ┌─────────────────────────┐
  │      WHITE PAPER        │
  │                         │
  │   ───|1|2|3|4|5|───     │  ← ruler flat on paper
  │          ↑              │
  │     (spot lands here)   │
  └─────────────────────────┘

STEP 2 - Mount the applicator PERPENDICULAR to the paper

This is the most important step. The applicator diode tip must point straight DOWN at the paper at a perfect 90° angle - not tilted, not angled.

     ┃ cable
     ┃
   ┌─┨─┐
   │ ┃ │  ← applicator body  
   │ ┃ │
   └─╂─┘
     ┃
     ● ← LED tip pointing straight DOWN
     |
     |  (air gap — this is your "distance")
     |
  ═══════════  ← paper surface with ruler

Why perpendicular matters: If the led is tilted even 15-20°, the spot on the paper becomes an elongated oval instead of a circle, and all measurements become useless. Take a moment to eyeball it - the applicator body should look like a vertical column above the paper.

STEP 3 - Set the distance to exactly 3 cm

Using your ruler or tape measure, set the gap between the very tip of the applicator (the clear dome where light comes out) and the paper surface to exactly 3 cm (30 mm).

This distance is critical. Please be as precise as you can - even 5mm off will affect the result. Measure from the outermost point of the clear tip, not from the base of the clip.

STEP 4 - Turn on the device, kill the lights

Turn on your Vielight. Make sure the intranasal LED is actually firing (you should see a faint glow through the phone camera).

Now turn off ALL lights in the room. Close blinds/curtains. The darker the better - any ambient light will wash out the NIR spot and make it impossible to measure.

STEP 5 - Photograph the spot with your phone

Open your phone camera (normal photo mode, no flash, no filters, no night mode). Point it at the paper from above at an angle where you can see both:

• The light spot on the paper
• The ruler markings

You should see a bright pinkish-white spot on your screen (the 810nm light) with the ruler visible nearby for scale.

Take 2-3 photos. Try to keep the phone steady (lean it on something).

STEP 6 - Repeat at 5 cm distance

Now increase the gap to exactly 5 cm and take another set of photos. Same procedure: perpendicular, dark room, ruler visible.

STEP 7 (OPTIONAL but awesome) - Repeat at 1 cm distance

If you're feeling generous, also do 1 cm distance. This gives us three data points which makes the beam angle calculation much more reliable.

📊 What I'll calculate from your photos:

From the spot diameter (measured against the ruler in the photo) at a known distance, the beam half-angle is:

FWHM ≈ 2 × arctan( spot_diameter / (2 × distance) )

With spots at 3cm AND 5cm, I can cross-check the result and also determine if the beam is truly collimated or just diverging randomly.

What a good result looks like:

• Tight, well-defined circle with clear edges = good collimation (what we want to see from a $1,800+ device)
• Fuzzy blob with no clear boundary = poor optics, basically a bare LED
• Ring pattern or donut shape = interesting, would suggest a reflector-based optical design

Would massively appreciate it. Happy to share the analysis results with the community afterward - I think a lot of people would benefit from independent beam quality data on these devices. 🙏