[Alibaba Adventure] GT-FC40: XHP35 HI's Bigger Sister, with 90+ CRI

Shouldn’t you wait for Djozz test results before posting the groupbuy? Most people are not going to buy without seeing what they are getting.

I should be able to at least do a proper beamshot and side-by-side comparison against CREE’s on a flashlight this week, provided I won’t destroy the driver.

I could always let Djozz chime in later. Djozz’s result should turn up next two weeks.

Also, the manufacturer seems quite confident about CRI values of this thing. They did said something along the line of “see it for yourself”.

I have no doubt it will reach 95CRI however I’m more interested in the tint at different currents and output at different currents.

I guess this week’s beam shot should serve as some kind of appetizer on the tint and output on one specific current. :wink:

I have both of them in a C8s host today.

I got beamshots too. Unfortunately, I only have one high drain 18650, and my setup trips the overcurrent protection of other batteries. I can only give you the individual beamshot for the moment.

All the shots are taken at 5500k WB. I took this with a smartphone camera which annoyingly messes with the exposure setting.

XHP70’s Beam shot

FC40’s Beam shot — Again, This looks much less green than XHP70’s 90CRI, but a bit cooler.

Additionally, the H2-C I ordered are not the same. One of them operates in 1-mode, the other operates in 5-mode. Annoying, but it’s only the best shot I have at this. I probably don’t want to go through the trouble of sanding down the driver and coat it with nail polish again.

Anyway, let’s light up an entire room.

The tint looks great compared with the greenish XHP70.2. Let’s see how output and efficiency test out.

I’ll wait for the test result but sound promising…see the beamshot…I don’t know if this is “going to be next new”…wow, :heart_eyes:

I did some very crude brightness measurement by shining the hotspot on a luxmeter at 1ft distance.

The measurement reads ~120k-140k lux on the highest mode (with the H2-C)

That equals to 11k-13kcd or 210-220m of throw distance in a C8s body

I’m now searching for the proper 20mm driver for these, but it’s really hard to find.

11k-13kcd in a C8 head seems very low.

That could be two things:

  • The nail polish coating isn’t perfect and there might be some low-key shorting which prevents the driver from pushing 1.5A, or prevents the driver from entering the turbo mode. Which I will figure out the way to measure the tail-cap current draw.
  • I might have overloaded the luxmeter and it stops scaling properly past 100k lux (which is it’s stated maximum range, although it continues to register the brightness over 100k lux anyway). I might try to test again from further distance and see what happens.

The hotspot shows much less tint shift than with the XHP70. I’m looking forward to this led in 4000K. Maybe I will use one in a Haikelite SC26.

Update: Light measurement at ~2.5ft (75cm). It seems like my suspicion about the Luxmeter overloading is correct.

XHP70.2 version:

Brightness @2.5ft: 34.5k - 35.5k Lux
Intensity Estimated Output: 20.0k - 20.6kcd
Estimated Throw: 283-287m

FC-40 version:

Brightness @2.5ft: 29.5k - 31.5k Lux
Intensity Estimated Output: 17.1k - 18.0kcd
Estimated Throw: 262-268m

By this setup, it seems like FC-40 produces about 10-15% less output than XHP70.2 (but there is quite a hefty cost moving up CRI from 90, of course)

75 cm is likely still too close. The main reason is that the beam is not fully collimated at short distances. I’m not sure what is the minimum good distance for C8 but if you can measure at 5m I think that should be enough.
Also, what you measure is not output but intensity. I’m nearly sure that at the same intensity XHP70.2 has much higher output.

I finally bought extra pair of 18650s and can now do side-by-side beamshots. Here you go.

Looks like FC-40 produces a lot throwier light than XHP70 in a C8s body.

Correct Agro, a minimum 5M throw distance should be observed for Standards.

On lights I’ve built with a mile or more throw capability I use 50M for testing. If you have the light focused for optimum distance, the V shape of the beam profile hasn’t come together at closer distances and the meter isn’t getting the concentrated light to show the true throw reading. After getting lights that throw a mile or more, I can’t think of a couple of hundred meters as being throw, gonna take 3/4 of a mile or more to consider it “throwy”. :wink:

I received the two samples yesterday, but need a few days for the test because life is quite in the way this week, no spare evenings in my cave behind the cupboard at least until the weekend.

Ah well, beat me to it. At least you can see the direct tint comparison today.

I will leave the long distance measurement to Djozz then.

Two weeks sure is a long time to wait in this instance. Oh well, nevermind, there he is.

I need this LED!

@rngwn, could we have a picture of the GT-FC40’s footprint, please, to know if it is the same as the XHP70’s footprint (in order to swap emitter of a 12V XHP70 flashlight with larger MCPCB) ?

I cannot see the underside of the emitter for now. I might ask the manufacturer for that, but the chances are pretty slim.