Focusing Reflectors, looking to tap some knowledge

Flashlight Modding and DIY Parts
1

I’ve recently started to develop an interest in throwers. Up till now all the lights I built were flooders, they’re just more useful to me but after building a DTS it occurred to me, throw is cool!

While getting the right beam with a flooder is easy, I find it much more difficult with a thrower, I’m hopping I can get some advice.

In particular I’d love to see some photos, LED too low in the reflector, LED too high, etc. Also, how do you folks get the adjustment just right, it seams easy to lower the LED in the reflector but what if you can’t get it to sit high enough, such as with a de-domed emitter?

I found this issue discussed in a couple of threads but not in great detail, maybe I just haven’t spent the countless hours needed to figure it out.

Here are a couple of pictures of a Jacob A60 for example. My apologies, the pictures were taken months apart, not at the same distance or against the same backdrop but I think I can use them to demonstrate my point.

First shot, Jacob A60 just the way it arrived.

Impressive little light but of course I want it just the way I want it, a little warmer tint from the LED and a little more power from the driver (1.8A at the tail as received).

Beam is nice and tight as purchased, measured about 65mm across the hot spot when 30” from the wall.
A small corona (if that’s the right word) just outside the hot spot then a few rings. At any distance the corona and rings are not visible at all and very little spill.

My thinking is the tight hot spot, small corona and little spill tell me that this is a well focused light as purchased.

Now for my “improvement”.

XP-E2, de-domed on Noctigon, focused the best I could achieve tonight.

Again, the photos, side by side are not relative except for the basic beam profile.
The XP-E2 de-domed is warmer and just what I was looking for in terms of tint. Using an XP-E2 will also allow me to go up a bit in current when I get around to the driver (I’m thinking 2.0A to get back some of the light I lost in tint and de-doming).

The focus however is a bit of an enigma to me.
The hot spot is again well defined and measured at the same 30” from the wall about 20mm smaller than original.
The corona however is huge! I can’t help but feel that’s wasted light. Spill is about the same as original.
The problem is if I adjust the reflector to reduce the corona the hot spot grows and the overall beam becomes less symmetrical. I can not achieve the same profile with the XP-E2 that I had with the XR-E.

Is this simply a limitation of the combination of reflector/LED I have or am I missing something? I understand that this reflector was designed to work with the LED the light came with.

Actually, as the light sits right now it’s pretty good, just not quite what I was looking for.

Any help would be appreciated.

Thanks

2

I have done the exact mod that you have done. I tried a dozen different spacers etc to the point of frustration trying to get it to measure as well on the light meter as the stock emitter. It was not until I used this that it worked properly. I use a light meter to tell me when things are right. Hopefully it is more honest than _____.

3

I have a variety of centering rings and spacers that I’ve been trying with mixed success.
I just ordered the ones you listed, I’ll see how they work out.

How does your A60 beam look using that adapter?

Thanks

4

Interested in this as well, would like to see some beamshots of emitters sitting too low or too high if someone has them.

5

On a white wall its slightly ringy with a very intense hot spot. No where as bad as the stock light was though. My reflector is not perfect as one of the isolators I was trying burnt and left slight smoke marks in a couple of spots that I cannot clean of the reflector surface. Outside the rings are not noticeable. I'm only running the stock driver with a pencil line on the capacitor so it starts on high all the time.

6

i just recently posted some photo of beamshots of a “fine focused” Reflector-based modifed Light ( a Defiant Super Trower ) in comparison to a BTU Shocker and Olight SR90, but i never did any photos of it in and out of focus.

7

That hotspot looks a lot smaller than the original, is that an accurate result of the difference between an xre and and an xpe2 emitter?
I was also planning on doing this to a Jacob a60, but I was hoping the hotspot size would be almost the same, just more intense with an xpe2….
Good luck with your reflector adjustments….

8

The hot spot is about 30% smaller than original, hard to say if it throws any better. If this rain ever lets up I’ll get outside and see how it looks.

I have some of the adapters MRsDNF used on order, I’ll try them and update.

I’ve come to the inevitable conclusion that the only way to get the optimal focus is to use a light meter.
Trying to judge the focus looking at a wall at X feet is just going to give me the best looking beam against at wall at X feet.
The problem with going outside and trying to judge the throw at XXX yards is it’s too subjective since I can’t do side by side comparisons.

I’ve put off buying a meter because I know once I do I’ll have to figure out how to calibrate my readings, how to check ceiling bounce and throw. Then there’ll be the spreadsheet to track everything, log the information for all 30-40 lights I have, from the little AAA lights to the 5D Mag.
Next will be putzing around with every light, hoping to achieve some imperceptible gain.

It will be 6 months before the kids see me again.

I really don’t want to buy a light meter!