*BLF LT1 Lantern Project) (updated Nov,17,2020)

[quote=SR-G]
Do you know which screws (with which dimensions) to buy and that would fit the BLT L1 screw holes ? I ordered these ones (flavor “LS047” / screw 4.5mm + additional height 3mm), and sadly they don’t fit well (and not in the same way between hole on the side versus at the bottom = it goes deeper on the side) (and i haven’t been able to find models without the “gap” in the middle).

Hi SR-G Just use a rubber washer to give you a good fit. Maybe something like a washing machine or dishwasher hose washer or a jumper valve washer. In the olden days, I used one on my camera tripod as the depth of the tripod screw hole varied from camera to camera.

https://www.aliexpress.com/item/1005001379528752.html?spm=a2g0o.productlist.0.0.2b6b5776m22IMd&algo_pvid=fe3fe785-e53c-4fe6-9fab-e423d3407894&algo_expid=fe3fe785-e53c-4fe6-9fab-e423d3407894-3&btsid=0bb0623916138088121807957ee5c3&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

So I’m in. What’s the best place to buy this ?

I have compared my LT1 to my Fenix CL30R and the fenix on turbo mode is quite alot more lumens than the LT1 sadly :frowning:
If the LT1 has those extra bridges soldered can it’s higher output stay sustained without overheating/having to step down?

Yes, the LT1 will get hotter and brighter but it will not use thermal step down.

Thanks, so will it get damaged running higher? I usually run it hours straight in up to 30degrees C static environment, Sounds like I best leave it stock.

Also I really wish they would put a 4 led volt meter on top of this, sorry but playing morse code with blinking lights is just unacceptable imo.

Temperature damage is unlikely. The LH351D are tested to 1000hrs at 3A at 85C. At 7*7135, each LH351D is getting less than 800mA at most.

The top might be so hot that it hurts to touch it, but it shouldn’t decrease the lifespan by much.

Even if something does break, the parts are pretty cheap to replace if you can do some soldering.

Hi
Does the Fenix CL30R have a built in volt meter ?

It has 4 led lights that gauge the SoC, not an actual volt meter with numbers. But so easy to use for the average joe.

Thanks

Does anyone know what the waterproof rating is on this? Can it handle rain?

It handles rain no problem. I have used them in the rain many times.

Great to hear, thanks!

I have a question. The LT1 doesn’t seem to be very efficient in its power usage; is that mainly because of extra circuitry to handle the tint mixing, or what?

Say the LT1 on high produces in the neighborhood of 600 lumens, for a bit less than 6 hours. The Q8 with the same 4 18650s can produce 750 lumens for something like 17 hours. The LT1 sucks juice a lot faster.

That’s not to take away from the advantages of a purpose-built lantern for specific uses, especially one that can vary its color temp output. I’m just thinking that when a person is camping, thrifty energy use from whatever cells one has packed can become a factor, too.

Where are those numbers; lumens and hours coming from? Are they reliable, realistic?

The LT1 is far from an efficiency champion, but the Q8 performance you suggest is not accurate. It would be nearly 250 lumens per Watt. No flashlight on the market comes close to that.

Since I’ve actually been curious about a comparison with the CL30R for a while, I went ahead and used this discussion as an excuse to make one, and I added the Q8 as well, since you brought it up.

In general, the LT1 compromises on efficiency for the sake of having high CRI (especially so at the warm end of the tint ramp). Based on Lumeniac’s photos, I suspect the CL30R is also high CRI. The LT1 and CL30R both compromise on efficiency for the sake of having well-diffused output. I assume the CL30R achieves its better overall efficiency by utilizing a buck driver (if a Lume1 or similar topology driver was ever offered as a mod for the LT1, I would be all over it!).

All of them are similar in size and weight, but of course, different shapes, and the CL30R holds one less battery. The Lumeniac review linked below has really good photo comparisons of the LT1 to the CL30R, showing by size and relative output under controlled conditions. A few users elsewhere have provided comparisons between the Q8 and LT1

I personally went with the less expensive LT1 with it’s tint ramping and Anduril, and am very happy with it. The Fenix looks like a really good lantern, too, and adds powerbank functionality and Fenix’s product support.

Comparison table (smartphones may need to be landscape orientation for best viewing):

BLF Q8 BLF LT1 CW BLF LT1 WW Fenix CL30R
Max Output (lm) 5,000 463 355 650
Efficacy (lm/W) 80 71 55 100
Regulated time on Max N/A 7 hours 7 hours 2 hours, 40 min
Color Temp 5000K? 5000K 2700K 4000K?
CRI 70? 90 90 80+?
Batteries 4 x 18650 4 x 18650 4 x 18650 3 x 18650
Weight @ 48g/cell 592g 597g 597g 556g

Sources:

Q8 Output: Advertised
Q8 Runtime Test: Zeroair review using 3000mAh cells
Q8 Efficacy: Calculated stepwise from Zeroair’s graph in combination with advertised output.
LT1 Output: Maukka Test
LT1 Efficacy: Calculated from Maukka’s based on 5 x 0.35A driver and 3.7V average battery voltage
LT1 and CL30R Runtimes: Lumeniac’s Review using 2600mAh cells
CL30R Output: Manufacturer specified (Not tested. See Lumeniac’s photos for comparison)
CL30R Efficacy: Calculated stepwise from Lumeniac’s graph and advertised output.

I got the Q8 numbers from a post by CivilGearReviews, which cited alleged mfr test runtime results. Note the “Group 8” data line in the chart.
CivilGearReviews thread
Not saying that I’ve done anything to confirm accuracy of those numbers, though.
I’m not comparing max output to max output, but rather m/l equivalent lumens of output.

Runtime of the LT1 at high setting has been mentioned by several people, and GreenCampfire did a runtime test and posted a graph showing almost 6 hours before output fell off sharply.

Maybe I missed it, but does anyone know what the button LED turning on halfway through the ramp signifies? Usually it’s the FET channel turning on in other lights, but the LT1 doesn’t have a FET.

It’s just an arbitrary value (65/150). It also doesn’t turn on, it switches to high (and is very dim before that).

I’d love to see an LT1 pro with a boost driver (buck has flickering issue) and a better thermal path which directs more heat to the body.