Collimation help

[HazenAL]

Hello everyone,

I'm designing a surgical headlight as a gift for my brother and boy have I gotten myself into a world of hurt.

I've been struggling with understanding how to collimate a Nichia E17A SM573-B12-R9080 @ 5700K

Specs:

• 120 lm output
• 1.7mm x 1.7mm x 0.3mm
• 120 degree
• 5700k
• CRI 90+

I am looking for some insight on a lens or lenses that address the following requirements:

• Circular beam with uniform lighting throughout
• Tight edges with least amount of halo/spill as possible
• Produce a 130mm (diameter) circle from a distance of 500mm
• Maintain colours after collimating
• I want at least 90 lumens after collimation
• This will be attached near the face so weight and lens diameter is a concern.

Attached is an example of the beam I am looking for and how the setup will be worn.

So far what I understand is that I need an aspheric lens(es) and my lens angle is about 15 degrees.
How do I find out the specifications of the lens that I need? and do you guys have any recommendations?

Thank you

 

[WizardG]

Google TIR optics for LEDs.

 

[Cyparagon]

I second the TIR option. Aspherics are okay, but they waste a lot of light if you want a tight focus. The edges of the spot are softer with TIR, but it's just too easy. Just glue it to the LED and you're done. No optics tube or threaded focus to fuxor around with. I have a few of these variety that I like: I've been using one on a goose neck spot light on my lab bench for the last few years. Last time I checked, these are the largest you can easily get. Only $1 too. https://www.ebay.com/itm/222560050938

5 degrees puts this one somewhere around a theoretical 75mm at half meter though, so maybe look for a 10 degree one. If you're insisting on a top-hat beam profile, aspherics are better. But you're not gonna get 90 lumens out the front.