Lumintop GT4

Please see post from Texas Ace:

key word above “real” lumens
He’s referencing Matt (vestureofblood) who tested the R90C and the results were significantly less than Imalent claimed output:
R90C claimed 20 000 test result 15 274 difference –24% less
GT70 claimed 7 500 test result 7 537 difference +0.01% more

Watch this video and it’s easy to see that the Imalent is brighter but the output doesn’t appear even close to 2.75x that of the GT70

Hey TA,

I believe that currently the only direct competitor to this is the R90C but I’m curious if you think that the MF03 concept will be in this class also? At first glance the MF03 seems like it’s more of an X70 competitor with its 7x xhp70.2 and single xhp35 hi. However, from the photo below all of the 70.2 reflectors are smooth finished rather than the standard orange peel. Shouldn’t that all add up to something like 20 000+ lumen with 700+kcd?

Without some more details and/or test it is impossible to say exactly what it will do but just looking at it, I would guess less throw (the center xhp35 might bias that but the beam would be very different) and or course the possibility of higher lumens, assuming they have a good enough driver to power it properly.

my MF03 draft was made a year before i heared of the X70...

I think he meant more as a general final performance competitor vs a flashlight designed to compete with another light.

LOL

Correct.

I currently have a few big lights that each cover a rather specific category:
DX80 extreme output - high flood - medium throw
MF04 low output - no flood - extreme throw
MT03TA extreme output - extreme flood - no throw

The GT & MF04 created a new category of extreme throw - low output/flood
The GT70 & R90C created a new category of high throw/output - mild flood (due to spill)
-I don’t personally consider the MF04S in the above category given it’s reported less than 1 minute runtime on turbo. otherwise sure it’s in.

The GT4 looks like it could amplify the high throw/output - mild flood category into extreme throw/output - medium flood (due to spill)

The DX80, X80GT, MS12 & X70 are just output monsters with no realistic throw in comparison to the new 1 000 000+ cd category. The X70 makes only 311kcd and has extremely small reflectors so to me the MF03 looks kind of in between with it’s deeper smooth reflectors was my guess. Maybe like a DX80 with extra throw?

Anyway… I’m stoked for the GT4 whenever it eventually comes out. I really like the idea of a mild/medium flood, huge hotspot, mega thrower! My MF04 is crazy but in the dark I basically can’t see where I’m walking. My DX80 is also crazy but using turbo in the winter basically blinds me due to the sheer amount of light reflected back at me off the snow

Or maybe it just looks cool and I’m good at rationalizing why I need more super expensive toys! :person_facepalming:

MF04C?

“S”… corrected. good catch!

Okay, I thought they where releasing a new model. Lol

do we actually have any beamshots or info about lumen output, runtime and temperature of the GT4 or are we just speculating and waiting for it to be released?

Texas_Ace has a prototype and the lumens numbers are as tested by him, there are some revisions to smooth out details but other than that the functioning light has been tested. :wink:

I did get a prototype in and have tested it but it has issues so I have not made the tests public yet until I know how they will be fixing them.

I can say the thermal performance is the best I have ever seen, With this much power it will still have to step down the output of course but it heats up surprisingly slowly considering the power. I am very pleased with the thermal performance.

The output is also good but sadly the LED’s died during disassembly/reassembly so I am unable to test it properly until I get replacements. They should be in next week.

Based on basic math though, 20k lumens is a very reasonable number I expect. The MT09R with 3x xhp70.3 and only 4 batteries can do ~18k lumens, so with 4x XHP70.2 and 8 cells it is not a big leap to assume that 20k lumens is well within reason assuming they get some good bin LED’s.

SOLD! NOW:

If the blf gt70.2 can push 7.5k-8k lumens, am I wrong in multiplying this by 4 and thinking this has the possibility to push 28k-32k lumens?

New to this. Just trying to learn as much as possible.

well in theory maybe yes, since this light will have no active cooling i think going over 20k is not needed imo. Better if they keep around that mark and make it run as stable as they can before thermal stuff does the job and steps down, but this is just me guessing unless lumintop wanna compete with acebeam and imalent in lumens war… Just looking at the few images posted i can imagine even at 20k lumens or so it will be an impressive light with 4 deep reflectors pushing what 1km throw or something ?

How are you going to limit the current of a FET driver?

Unless the driver is a buck+FET driver, you won’t be getting less than 20k lumens in this light, personally knowing it’s going to be in the real of 28k lumens+ instead.

Indeed, with 8x18650s and dual silver plated BeCu springs in the carriers, and a thick short dual silver plated dual BeCu springs, current is going to go amok.

Kinda sorta. You never get exactly 4x the output due to resistance and other factors but yes, it is safe to say I am being conservative in my 20k+ lumen estimate.

You can limit output on an FET driver by simply limiting the max PWM. The efficiency difference is surprisingly small vs a buck driver at high PWM levels.

OR, use lesser cells to limit output… like a Panasonic B vs a Samsung 30Q. Availability of amperage will be a deciding factor to a degree, setting PWM values lower will take it further.

In my own experience heat at the emitter shelf will be a deciding factor when utilizing multiple 70.2 emitters, while a single 70.2 can indeed be run pretty hard the accumulated heat of multiples tends to knock out individual dies in the 4 die array causing failure. This light is designed to handle quite a lot of heat, remains to be seen if all 4 emitters can handle the output of quality cells over extended times of full Turbo operation.

In my own builds I have found it can be exasperating having these die failures, losing one, two, then all 4 dies and having to replace the big emitters. So yes, I am very interested in seeing how this goes… given I can even afford this light I will plan to find out for myself how it performs. I DO like how it’s made and give Kudo’s to Lumintop for their efforts. :slight_smile: