Why are R2 lights now becoming popular?

[sparkysko]

Did I miss something. When I ordered my Nitecore a long while back, it came with (and still does) a Q5. R2's have been available for almost 2 years now, but only now it seems are people making the transition to R2 from Q5, and now XP-G R4's are coming....

What gives?

Also, I haven't been able to find any R2 stars that are similar in size to these Q5 stars (16 mm or so) for 1xAA lights.

 

[Moonshadow]

Limited availability and only a slight increase in light output. Why pay ten bucks more on a D10 when you'll probably never notice the difference ?

It also seems that you get a bit more of a tint lottery on the R2s. It's a manufacturing process, so when you push the boundaries on output, you end up with less control on the colour. Coupled with the limited availability probably means that manufacturers have to take what they can get.

With a Q5 Nitecore you know that you will get a pure white WC tint, but the R2s can vary quite a bit - I have a yellowish one in my D20, and other people have reported R2s on the bluish side.

 

[monanza]

For me, R2 (or its equivalent V bin) makes most sense in small form factors (1xCR123, CR2, AA, AAA, 10280, 10180) where heat dissipation, battery capacity, and discharge rates are severely constrained and efficiency becomes paramount. A 5% improvement in emitter efficiency translates to roughly 10% less heat (for the same lumen output,) all other factors being equal. This is nothing to sneeze at. It makes the light more reliable, promotes longer emitter life, and reduces the frequency at which batteries have to be swapped or recharged.

It looks like die manufacturers have refined their R2 process and are making the R2 bins mainstream. R2 availability has improved, making them more affordable than they were a few months ago and making color bin selection a little easier. As to flashlight makers, there is always a race to provide the highest output and most efficient lights if only for bragging rights. In that area however, circuit efficiency and good thermal design for heat dissipation also play key roles.

For these and other reasons, I do not balk at paying an extra few dollars for a premium R2 bin.

Edit: Note also that battery sag (voltage drop) decreases with decreased emitter current, which means the circuit draws even less current from the battery.

 

[old4570]

Yeah , limited availability on 16mm or smaller bases ..

And yes , very shortly XP-G R4 ... XP-E was ?? Disappointing .

And what ever happen to XR-E R4 ? Would have loved to see some of those .

 

[litetube]

I would agree. Basic economics here on both the production and sales.

Cree can mass produce the Q5 more efficiently/consistantly for less thus keeping the cost of the lights they are used in down resulting in better sales of the lighting devices.. Who really cares about the difference in the real world? Noone except us here

The Q5s are available in large quantities .

I do think the path will be towards the XPE and XPG s with smaller dies for the smaller single cell lights (I am really liking my ITP A3 Eos )

Once again it will be a matter of the manufacturer being able to produce them in large quantities cheaply

 

[qwertyydude]

Q5's from DX I think offer the best color. I don't know about you but every P4 I got from there was tinted green and R2 is just a tiny bit bluer.

 

[Marduke]

Q5's from DX I think offer the best color. I don't know about you but every P4 I got from there was tinted green and R2 is just a tiny bit bluer.

Flux and tint bins are completely independant.

 

[Moonshadow]

In theory, yes - but in practical terms there is a manufacturing process and supply / demand to consider, hence the following explanation:

It also seems that you get a bit more of a tint lottery on the R2s. It's a manufacturing process, so when you push the boundaries on output, you end up with less control on the colour. Coupled with the limited availability probably means that manufacturers have to take what they can get.

In other words, since they are in shorter supply, a manufacturer might have to accept R2 LEDs from a wider range of tint bins to get the number that they require.

Just look at these descriptions from 4sevens site:

• Uses a highly efficient Cree XR-E Q5 WC LED lamp.
• 130 lumens at maximum output.

• Uses a highly efficient Cree R2 LED lamp.
• 145 lumens at maximum output.

It is probably no coincidence that the Q5 versions guarantee a specific tint bin (WC) whereas the R2 models do not.

 

[Toaster]

They're not becoming more popular. R2 LEDs have always been popular. They're just becoming more available now. 2 years ago there wasn't enough supply of R2 LEDs to allow them to be used in mass production of flashlights. Don't confuse availability with abundance.

 

[Sgt. LED]

I liked the little XP-E!!!!!!! :shrug:

It could fit lots of places the XR-E couldn't and the beam was much easier to fine tune. It could give you throw without the Cree ring and still provide the flood of an OP reflector while using a smooth one.

 

[WadeF]

I liked the little XP-E!!!!!!! :shrug:

It could fit lots of places the XR-E couldn't and the beam was much easier to fine tune. It could give you throw without the Cree ring and still provide the flood of an OP reflector while using a smooth one.

I don't think the XP-E is going anywhere. It may still have advantages over the XP-G, such as more throw when used with the same size reflector. The XP-G has a larger die than the XP-E, but the same foot print.

As far as XP-G R4 vs XP-E R2, I would guess the larger die size of the XP-G gives it an edge in efficiency allowing it to achieve the R4 status.

As XP-G's become more plentiful we'll have to wait and see which makes more sense for certain types of lights, XP-G or XR-E.

As far as R2 lights now becoming popular, that's news to me as I thought they were popular for the past year or two. Many of my lights have XR-E R2's or XP-E R2's in them.

R2's have been popular, but were more limited to premium lights, special runs, etc. Q5 was the standard for most lights. Now R2 maybe becoming the standard, but I suspect we'll see more lights moving to XP-E R2 and XP-G R2, R4 as they produce a much cleaner beam. While companies like Liteflux have achieved clean beams with the XR-E they do so at the expense of a wide beam, the spill is more narrow and the reflectors have a pretty heavy texture which may reduce the reflector's efficiency. The XR-E and XP-G work well with smooth reflectors, or very lightly textured reflectors.