Does anybody have any idea how many lumens (roughly) I would get if I put this red lens Fenix Filter Adapter AOF-L Head Diameter 40 mm | Fenixtorch.co.uk
on say a 1000 lumen white led light ?
Or is there some sort of calculation I can do to get a rough figure ?
I have tried to open same discussion about special low range plant grow leds vs high-cree white leds.
I think problem is inside measurement tools that we have. Who knows how cheap lux meter measures not white leds (for example, UV with black filter)?
My question is because I want a red light headlamp for night fishing using surface lures to not spook the fish.
I still need to illuminate about 50m if possible.
I have not found a commercially available headlamp with a strong red output just lamps with red leds secondary to the main white & only putting out say 13 lumens such as the Nitecore NU10.
I have tried the red lens in my link on a cheap Chinese zoomie I have as I cannot find a red lens to fit any of my good powerful headlamps.
The Chinese zoomie is no more than 300 lumens, maybe only 200, & with the red lens fitted it is nowhere near enough light.
I have good headlamps with from 1000-1500 real lumens (Nitcore HC60, Olight H35 etc) but cannot get red lenses for them.
I was wondering if I custom fitted a red lens to one of these good lamps what sort of output I could expect ?
I think if you look to specs of zebralight headlamps with red led, you will find most believable specs.
Another problem, your eyes feel red light another way, you cant just compare 200 lumens white light and 200 lumens red light.
Yes I realise that but whatever amount of lumens of red light the Chinese lamp put out it was nowhere near enough for my needs.
I think that the lamp in question is probably 2-300 lumens (lattice bright emitter claimed 3000 lumens) & without the red lens will light up enough/far enough for my needs but with the red lens I was only able to see maybe 5-10m certainly no more.
I am just wondering if what I am suggesting, modifying a red lens to fit one of my powerful headlamps, will work before buying a red lens & butchering it to fit.
Or is there a headlamp available that will suit my needs as stock ?
There’s not much red in low CRI LEDs, so you would want to put it in front of a high CRI LED or use a red LED.
Especially low CRI cool or neutral white have very little red output.
One more problem. Without detailed spectral tests, we dont know what wavelength this filter absorbs and what goes through it.
Your idea is not bad, it was used in car brake lights for years and still very popular.
To get more than 200 lumens with red leds, you need to make custom triple/quad headlamp.
I am wondering if some Red diffusion film cut to fit the lens might do what you need?
EDIT: I don’t know what the Lux readings or lumens are when the filters are used , but I have a big search light that I did a review on a good while back and the red lens cut the light way down compared to the green and the white light.
Also the newest green colored Maxtoch 2X gives a little more light further out than the red does.
There is something with the color spectrum though that my light box / meter will not give me a lumens reading with the colored lights.
Here are some beamshots of that search light at 125 yards with all 3 colors if it helps at all.
I have found that the answer to this question is highly dependent on both the led and the filter used. I did some testing with a sample pack of lee filters. There are a number of red filters that I tried on a number of leds. When changing the filter wavelength there seemed to be one that appeared much brighter than the rest but this one was not the same for every led tested. I think kariba has revealed the reason for this. In general, I got the brightest red from filters closer to the orange side of red and with very bright neutral white leds. I suppose this doesn’t help much but maybe it gives some insight…
Did a test with a Nichia 219B Lumintop Tool (CRI 91), Eagletac MX25L3C (CRI 87) and an MT-G2 Haikelite SC02 (CRI 69) with the filter that came with the Eagletac. All are neutral white.
Tool (CRI 91)
No filter: 548 lux
Red filter: 123 lux
Loss: 78%
MX25L3C (CRI 87)
No filter: 6666 lux
Red filter: 1297 lux
Loss: 80.5%
SC02 (CRI 67)
No filter: 5514 lux
Red filter: 1051 lux
Loss: 81%
Spectral effect of the filter:
So, we can have near 20lm/w with no light under 570nm wavelength. Looks slightly less than xp-e2 red.
a 6500k CRI 70 light will have significant less red than a 2700K CRI 80or90
I’d recommend just getting any P60/P90 light, and roll yer own drop-in with a nice XP-E2 red emitter. Or go crazy with a triple.
The small chip in the -E2 will give really nice throw in a reflector light. Want killer throw, use a C8 (older, with pill, vs newer with integrated shelf), and you’ll light up things nice and red really far out.
You can use the C8 with the integrated shelf, only it’ll be a bit tougher to do the soldering directly in the head vs a nice easy-to-diddle-with pill.
With a nice thrower, you don’t need bulk lumens to light up things, as it’ll concentrate the light where you want it.
I need this red light in a headlight not a flashlight.
It is to illuminate the surface when night fishing with surface lures without spooking the fish.
1000lm in a headlamp, sustained? You get an asbestos bandana to keep from frying your forehead?
If easy(!?) to get to, I might suggest an emitter-swap, but be sure to keep it throttled down. E2s can’t take too much abuse if not properly cooled. I’d recommend ~1A max.
You put the flashlight into a headband designed to hold flashlight.
Voila! Headlamp!
In that case, forget the C8, and use an S2+. Easy-to-remove pills, easy to mod, swappable for any kind of 20mm TIR lens to go from 5° spot to 120° flood (just ordered a few 90s and 120s, as I only have 60s as the floodiest so far).
Can even use a shorty tube to fit only an 18350 to make it even lighter.
No it doesn”t have to be sustained just a good amount of light available when needed & doesn”t have to be 1000 lumens I only mentioned that as my HC60 is 1000 lumens max & if I could get a red lens to fit it would be ideal for my needs IMO as it is light, compact, powerful & comfortable to wear.
Unfortunately the emitter bezel is tiny at about 18.45mm od & I can”t find any push on red lens under 23mm AFAIK.
My Olight is 1500 lumens max & doesn”t get that hot at all 
but is not as compact having a triple emitter head, is heavier, has a separate belt mounted battery pack, not as comfortable & due to the head shape a red lens would be impractical.
Might look a bit retarded, but that red filter-tape to use on busted taillights might work. Should be “Portland orange”, ie, “traffic red”, ie, orangey-red.
You could make your own filter to fit whichever light you like?
It would be easiest to order a small sheet of red film from Lee Filters. Cut it to the size of your lens, unscrew the bezel and put it right over the existing lens and re tighten the bezel. Or do the same with a piece of 1-2mm red plastic square from aliexpress. It’s tougher to cut though.
If you can get a filter on your hc60, I think it would be just enough for you.