SFT-40 vs CULPM1.TG vs YINDING 5050 30W in C8 reflector

Recently some new LEDs showed up so I thought I would replace my old WildTrail D80 v2 with something new.
Here’s some background to understand my intentions: my typical setup is a headlamp (currently FireFlies PL47) + a thrower. I use flashlights daily when walking the dog and this is 95% of my flashlights usage. This setup is most convenient for me because I have free hand while walking, but when something catches my attention (e.g. shiny eyes looking out of the darkness) I get the thrower and check what’s hiding there. So my thrower use is limited to 10-30 seconds until I find out what’s hidden in the darkness. Then I shut it off and put into pocket again. So my thrower has to be pocketable too. C8 class is quite obvious since it merges these two conditions: throwy and pocketable.
All right, so we know what body will suit most. Let’s go further.
Driver and LED. The driver decision was easy: L4P! I know MTN Electronics does a great drivers too but considering the price and shipping time - L4P won.
The LED was the biggest consideration and required some tests to get comparable numbers. Naked eye is just too imperfect especially when it comes to higher brightness. I narrowed my considerations to 3 LEDs however I hope to add more within the time as I get more of them tested. Well… tested maybe is too sublime word. Let’s call it checked.
I have to justify myself, I’m an amateur so neither my methodology, knowledge nor equipment can be called authoritative, but on the other hand I did my best to do it reliably, repeatably and reproducible. So I took 3 LEDs, 3 drivers and 3 hosts and compared them. I took those working on higher amperage since high heat generation is not a problem for those 10-30 seconds. I’ve arranged a measuring distance of 9m. I know it should be as big as possible, but I wanted to do it indoors and 9m was most I could get.
So this is how it went:

Starring (all have the same SMO ref):

Luminus SFT-40 “(test link)”:Luminus SFT40 test
Osram CULPM1.TG “(test link)”:OSRAM CSLNM1.TG & CULNM1.TG 1mm², CSLPM1.TG & CULPM1.TG 2mm²
YINDING 5050 30W “(test link)”:Yinding "5050 30W" round die domeless led tested

Methodology:
For each configuration I’ve made 4 trials noting the result each time. Then I took average of it. Each measurment was done 10 seconds after turning it on. There were a few amperages checked to figure out what’s the most suitable for a particular LED, within the range of 7A-9A. Luxmeter UT383 from UNI-T was used with a MAX function to read the peak value.

Results:

Here are the results. I’ve also added some other flashlights just to have a better comparison but for the test only the above metnioned 3 LEDs played a role.
As you can see it wasn’t easy to draw a winner. Results were so close one to another and the standard deviation was often exceeding the diffrence between readings, so I cannot call it an obvious conclusion. But basing on the readings and on the personal impressions from outdoor trials I’ve managed to drawa the winner.

Ladieeeees aaaand Gentlemeeeen…. The winner is: LUMINUS SFT-40! Simply - it gives same throw as Yinding and Osram CULPM1.TG, but it’s wider.

And here are some shots but honestly - the throw for the naked eye seems to be the same.

Luminus SFT-40:

Osram CULPM1.TG:

YINDING 5050 30W:

My personal conclusions are:
SFT-40 is hungry for Amperes. More power results in more Candelas. Big (5050) LED which has also advantages - better heat dissipation, easy to replace other 5050 LEDs.
CULPM1.TG above 7A is not feeling well. It’s sweetspot is somewhere around 7A, no sense to drive it higher since you get only more heat.
YINDING 5050 30W is a breakthrough LED if it comes to die size vs emitter size. A truly narrow beam in a bigger (5050) housing. Like the Osram, I don’t see any sense in feeding it with more than 7A

But to be honest… at 7-8A all of these are great and outperform all the other LEDs that I have dealt with so far :smiley:

Thanks for reading. I hope to extend this thread in the future but recently I’m too busy.

Edit 21 Dec 2021:
Just found a little time to install OSTAR LE UW Q8WP 20W in a C8+ body. The result was very satysfying for me so I wanted to share it with you guys asap.

The measurement is at the bottom of my table (above). With a Convoy 5A driver (springs bypassed) it gave 878 meters of throw which I consider great at this amperage. Furthermore it’s tint is consistent across all the modes/amperes which differs it from many other well throwing LEDs. I concluded it upon my bare eye and white ceiling but - for others this test was not that favourable.
Secondly - I haven’t measured it but judging by the beam it may be a competitor for White Flats from Osram. It’s beam is narrow (something between W1 and W2 I’d dare to say) but gives more spill to the sides. And it seems the 9mm hole SMO ref from C8 suits it well.

Here are some pictures:

Thank you. Nicely done. Would love to see that Yinding in an “L” series or Mateminco/Astrolux FT03 host.

Im pretty excited to get my m21a wirh sft-40 from Simon. I do a lot of off leash walking so I like seeing what’s in the trail ahead.

Nice work, though I do have one observation to share.
My first “throwers” were converted stock C8 flashlights. After a while I started buying hosts and specific parts. The possibilities of the second option are wider, but it remains a bit of a quality lottery. At first sight (seemingly) identical parts perform different when put in front of a while wall or a luxmeter. My remark boils down to this:
The Osram emitter has a 3535 footprint and the other two have 5050 footprints. So in combination with the Osram emitter I bought some “Aluminum Alloy Smooth Reflector for Cree XR 42*31mm” at Fasttech (partno. 1575100). And my first impression is that these work better for the Osram emitter. Causing a narrower hotspot.
The FT XR reflectors are different from the Convoy XM/L reflectors. The hole is smaller (ca.5mm vs. ca.9mm) and it is surrounded by a flat surface that extends further (outside diam. ca.15mm vs. ca.13mm) than the bigger hole in the XM/L reflector.

Great comparison 1stein! Thanks for doing all the work.

Nice really really nice.

1stein,

What camera do you use for taking such good pics?

Just phone. It’s Huawei P30 Pro.

Do you use some kind of exposure settings and how do you do phone and flashlight fixation (with tripod or something)?

With your pics at 7A that round Yingding is a winner and it does not seem to have green tint at all as most guys reported?

Thanks Hank for sharing this. I’ve used stock reflectors but this part has a huge impact on the beam indeed. Following your example im going to order the XR refs right away.

Yes, I can, but I just don’t play with all those settings. Maybe if I had a tripod I could do it.

Referring to the green tint - i could observe it only at lower Aperage. It was really fine tint within the range 7A-9A.

Did you used LD-A4 or LD-B4 driver?

I used LD-A4 with 18AWG wires and small copper cylinder soldered to driver’s “+”. Also put some heatsink silicone tubes into the driver’s chamber to extend LEDs life.
All the pictures/measurements done with 18650 Sony VTC5 (freshly charged).

This is how it looks:

Heatsink silicone tubes? Hmmm… What that could be :question: Something like silicone thermal blocks?

Sorry for the typo, I meant Cubes, not tubes :person_facepalming: my bad.

KD lists this as Thermal Conduction Silicone Rubber Cubes

PS: they feel cold at touch so maybe the thermal conductivity is not that bad

Yes… They surely help at cooling down the pill although real potting compound is much better but it is permanent solution. At 7-8 A current draw it is not bad idea to put that silicone cubes in driver pill cavity :+1:

Very nice, thanks for all that effort! To my eye the Osram still looks a tad better although I really like the couple of SFT40 that I have (not in C8 hosts). I’m running the SFT40 at 5.6A and 7A and I just hope they don’t suffer the black spot syndrome in the future. We know the Osram is pretty robust over time.

Wonderful photos with such clear air at night! I don’t think we ever have air like that at night where I live. :slight_smile:

The pleasure is entirely mine :face_with_monocle:
Wish I had more time for researches like this, but earning for all those flashlights takes time :sunglasses: