Which LED for practical thrower?

You can see the archived poll results on the Wayback Machine:

https://web.archive.org/web/20221220093741/https://budgetlightforum.com/t/-/72801

For those that want a throwy light, which LED do you think is the most useful? Overall distance seems like it might not matter as much as total light on target. Would be looking for 1x18650 if that influences LED choice.

i.e. I might prefer a well lit target at 50m rather than something at 300m that I can barely make out.

Usage would probably be just around the neighborhood, camping, etc.

Really wish I had something like this while on safari at kruger national park but I didn’t realize they let you bring your own lights!

XHP 35.2 doesn’t exist.
My pick is XHP35 HI (marked “other”).

Does the XHP35 HI have more throw than the 50 despite being smaller?

I understand that an LED with a smaller die throws better than one with a larger die. But then I’m probably wrong. :smiley:

Out of those three on typical drivers, easily the XP-L HI, excellent balance on intensity, acceptable tint, lumens, and voltage curve. Also actually a 3V LED so it is readily driven by a single cell setup.

This is not always the case, but often it is right.

Here:
XHP50.2 throws slightly better than XHP50.
XHP35 throws better than XHP50.2.
XHP35 HI throws much better than XHP35.

Throw is closely related to beam intensity. Die size is closely related to beam width. A smaller LED will produce narrower beam, but often a more intense one.

What about XHP 35 HI vs. XPL HI

The XP-L has higher intensity and can handle higher currents because it has a smaller die and produces less waste heat.
Not always the case that smaller = higher intensity though.

XPL HI
More efficient and (cheaper?) on single Li-Ion battery. Throws relatively far with decent runtime (assuming you’re using good host). XHP35 requires boost driver which mostly are still not as efficient as a good buck driver. With buck driver, battery options also broader. You can use high capacity medium drain Li-Ion.

- Clemence

For single 18650: XP-L HI

For me “Practical” means that it has a good amount of usable spill. So, we’re not talking about “thrower” lights, but just “throwy” general purpose flashlights, right? Of the choices given, I’d definitely choose the XPL HI for a single 18650 light.

Cheaper, but not more efficient. The LED itself is less efficient negating the buck driver benefits.
Furthermore:

  • There are far more drivers for XP-L HI, but linear ones (read: less efficient). There are some with superb UI too.
  • there are very few 1s buck and small 12v boost drivers and AFAIK nothing top notch on the market. There is however an excellent boost driver on the horizon
  • with XP-L HI buck driver would fall out of regulation quickly

XP-L HI would be significantly more throw-efficient, that is would produce more cd/W, but not so much with lm/W.
However the OP seems to need lm more than cd really.

And last but not least: with the upcoming driver XHP35 HI will produce 2500 LED lm in turbo. XP-L HI with buck driver? Can’t find anything above 2A so 750 lm?
I think that FET (+N)+1 makes more sense with XP-L HI but then it won’t come close to XHP35 HI efficacy. Much cheaper and good enough though.

At what range do you think the XPL HI might start making more sense than the XHP 35 HI?

Practical here also mean sensible driving current, at least to me. If the flashlight requires step down then (again, to me) it’s not practical. At lower “sensible” wattage XPL HI will have more candelas than XHP35 HI. Let’s say 1,5 A
You mentioned 2A current for XHP35 HI? That equals to ~24 watt output power. With good driver that requires at least 26 watt input power. No practical unless the flashlight is big enough to sink that waste heat. You also need to use high drain small capacity battery. Using above example you need to dissipate roughly 19,2 watt of heat (70% from the LED and 10% from the driver).

EDIT: at the same 2A drive current, an XPL HI will outputs “only” 6 watt of power. Using good buck driver (95% efficiency is common these days) you only need ~6,3 watt of input power. Waste heat would be somewhere around ~2,1 watt. That is very safe for most practical flashlights form factor

- Clemence

Frankly, I find it useless to compare currents to these LEDs.
At the same current they have vastly different power consumption as well as vastly different performance. Compare them at the same power and you’ll see different picture:

That’s LED alone, driver will reduce the difference to the point where they are not much different.

I disagree that turbo modes are not practical - if you want to take a look somewhere farther than your flashlight allows otherwise, you have 2 choices:

  • walk to some place closer to the target, so your regular mode can do the job
  • use a turbo mode

I would argue that the latter is more practical. But at the same time I think that sustained and near-sustained performance is very important.
Here we have a buck driver that can sustain 750 LED lm.
And a boost driver that in a good host should be able to sustain 1500 LED lm.
Since XP-L HI is smaller, it has ~40% more cd/lm. Therefore unless there’s a better driver than the one that I’ve seen,
XHP35 HI will offer:

  • higher sustained throw
  • much higher sustained output
  • turbo mode
  • similar efficacy
  • lower throw-efficiency
  • way better UI
  • at way higher price

If we compared XHP35 HI to XP-L HI with linear+FET driver, the picture would be different:

  • lower sustained throw
  • higher sustained output
  • wider beam
  • higher efficacy
  • lower throw-efficiency
  • same UI
  • at higher price

There’s no simple answer. In the one below I’ll assume the use of Shocki’s / Lexel’s boost driver which should be available soon. And FET+1 / FET+N+1 / high-end-linear driver with XP-L HI. With other choices the picture would be different.
In the same host, XHP35 HI will always have a wider beam. Assuming the same intensity, this is usually a good thing regardless of distance.
The difference comes where approaching light’s limits.
In turbo XHP35 HI will offer similar throw (with wider beam) at the cost of shorter turbo time.
Sustained, XHP35 will offer more lumens, but less throw.

So unless you’re constrained by runtime:

  • in turbo, XHP35 HI will be better unless the turbo time becomes too short for you
  • sustained, XHP35 HI will be better up to the distance where you stop seeing clearly. Which depends hugely on:
    • host
    • conditions
    • your eyes

I don’t feel able to provide any distances, sorry.

Hi Agro

Thanks for your thorough replies. But….
Did you not see the poster requirements at earlier post? He only needs 50 meters of throw. I’m not going to argue about the benefits of using XHP35 over XPL, I simply answered Nquin’s needs for his simple and practical uses (around the tent).

- Clemence

Just for preservation purpose

You are right, I certainly went too far into theory.
I still think that XHP35 HI would be better if we take the price out of equation, but I think the question was wrong really. OP should be comparing lights, not LEDs.