I don’t know if this new rendition of the C8 reflector matches previous ones, but I’ve read people saying to even try dropping reflector down over emitter without a spacer. Well it won’t go that far. The outter lip at the opening prevents that. See measurements. So shaving off about 1/2 the bottom thickness of the spacer is the max.
I’m wondering if there is a concensus on focus for this setup. I turned the spacer down to 0.64mm and got these results, up close. But fail to see any difference at 200 metters (600 feet).
Interesting topic. I’m surprised there isn’t more discussion on reflector focus as it can make a big difference in output and beam profile. I have this light, but haven’t touched it yet.
From the pictures it appears that the modded one has a more defined hotspot but the hotspot doesn’t look any brighter while the spill seems dimmer. Does the modded version look to have less output from your perspective?
Are the two beamshots the same flashlight or different ones? It looks like 2 flashlights side-by-side with different color temp emitters to me? Unless maybe they are 2 pictures merged but with different color temps in the pictures.
At least in theory a tighter hot spot should correlate to more throw but you might be at a threshold of diminshing returns where you can’t really tell the difference in practice.
I often use dedomed leds so I always end up trying to get the reflector closer to the ledboard, by thinning the base of the centerpiece, like you did, often also by sanding the base of the reflector down (if possible without completely loosing the flat bit of the reflector, so the centerpiece can still be used).
I actually had 2 lights, side by side in the same pic snap to try to avoid exposure auto setting differences. One modded one not. Set at a lower brightness level and only few feet from wall.
I’m sure this is correct. Auto correct can change the color temp as well. I’m having this problem right now trying to capture 3500lumens from an s41s with a cell phone. every mode above 2 looks the same. :person_facepalming: I’ve always wanted a real camera maybe it’s time to save up. I’ll like something especially for documenting mods. Mostly close-ups. There’s so much out there though. Hard to know where to start.
Ah… ok. The modded one does look like it has more throw then. Which is interesting because I have found that lowering the emitter that far into the reflector does the opposite. But each reflector is different I suppose.
I do this anytime I build a Convoy C8 with a dedomed emitter (eg, XP-L HI). Like djozz, I sand the spacer down as far as possible. It definitely seems to help bring things into focus.
Just because the hotspot is smaller does not necessarily mean it is more intense. The focus adjustment could have just taken some of the light from the hotspot and moved it to the corona.
One check for focus you can do is look into the beam at your test distance of 5m or so (with “solar viewing” glasses or some other dimming screen) and check if light is filling the reflector. An unfocused reflector will have the outer perimeter or inner region dark (not reflecting light from the LED). My definition of optimally focused is to have the entire reflector filled with light over the greatest angle (moving your eye in and out of the beam). This arrangement leads to the largest hotspot.
Having the reflector rest on the lip is not an issue, feel free to remove the spacer and let it go as low as it can while resting on the lip or sand the ring down more.
Due to how our eyes work even rather large changes in lumens or throw are very hard for our eyes to notice.
For example running a light at 800 lumens or 1100 lumens is a hardly noticeable difference to the human eye.
Not as much as you might think, that is actually how a perfectly focused light should look. The hole at the base of the reflector should be shown in the beam.
Flashlight reflectors purposely de-focus the beam slightly to remove this although if you hold any light close enough it should still show a hole in the middle of the beam.
I think I may need to go find a large drive in theater screen to use as a far distance target. 600 feet to the trees probably not the best for calibration.
That is debatable and the only way to say for sure is with a light meter. Although all else the same, the tighter hotspot should be brighter. The question is does the hotspot remain smaller at a distance or does it start spreading out due to the imperfect focus. Hence, a light meter is the only way to know for sure.
I noticed when I set the reflector down directly under an overhead light, that the light was focused to a pinpoint in the bottom hole. By moving the reflector w a bottom underneath closer to the light source did not change the focus.
The dimensions of the Convoy centering ring and height of the emitter place the top of the emitter flush w bottom of reflector. So I cut some shims to simulate what moving the emitter up into the reflector would yield. Wondering if this is a legitimate approach, given I dont have a light meter.?.
So should the size of the focal point be equal to emitter size?
Instead of lowering the reflector maybe use a thicker mcpcb like a Sinkpad or Noctigon to raise the emitter up to the reflector. Or am I missing something?
!
!
!
