brightness of an R2 sidespill vs an XP-G R5 sidespill ??

[radu1976]

Has anybody noticed the brightness of an XP-G R5 of the sidespill ?

According to www.light-reviews.com for an R2 the sidespill has 120-200 lux for the flashlights with a P60 size reflector - see EAGLETAC, DEREELIGHT, FENIX, SOLARFORCE, WOLFEYES FOX -
The EAGLETAC T10C2 seems to have the brightest sidespill - 218 lux - and overall brightness also but all come with the cost of the runtime
Does an XP-G R5 put more than 300 lux in the sidespill if we consider a 1hr runtime with RCR123s or 1.5-2.5hrs runtime with the 18650 cells ?

 

[don.gwapo]

My R5 spill is brighter than the R2 I have and the R5 has a bigger hotspot. It also has a wider spill like 12+ inches. Only drawback is my r5 is more on the flood side while the R2 has a tighter hotspot for throw. But I do love them both.

 

[IMSabbel]

Sidespill is just light that comes directly from the LED, i.e. not focussed by the reflector.

Comparing inside the XP line it is easy: Same radiation pattern means sidespill is equal to total lumen output, meaning an XP-G will win against an XP-E or XP-C

With the xr-e its a bit more difficult because of the more narrow radiation pattern.
At the same lumen output, using a normal style reflector (i.e. less than 45 degree opening), an XR-E will have:
- brighter spill
- smaller hotspot
- less total lumens in hotspot

Another point: reflector deepness: XP-G will have higher spill for big angles towards the side, as XR-Es are "prefocused" by their dome to radiate forward.

Of course, if you drive the XP-G high enough the gain in efficiency can offset these effects.

 

[gcbryan]

Has anybody noticed the brightness of an XP-G R5 of the sidespill ?

According to www.light-reviews.com for an R2 the sidespill has 120-200 lux for the flashlights with a P60 size reflector - see EAGLETAC, DEREELIGHT, FENIX, SOLARFORCE, WOLFEYES FOX -
The EAGLETAC T10C2 seems to have the brightest sidespill - 218 lux - and overall brightness also but all come with the cost of the runtime
Does an XP-G R5 put more than 300 lux in the sidespill if we consider a 1hr runtime with RCR123s or 1.5-2.5hrs runtime with the 18650 cells ?

I'm not sure what you're really asking. Lux is a measurement at a specific distance so your question can't be answered without more info in that regard.

I also don't see what the battery or runtime has to do with spill?

If you want to know how a XP-G R5 compares to a XR-E R2 as far as the beam is concerned the hotspot in the XR-E is brighter and smaller than in the XP-G. Its spill is greater since less of its beam hits the reflector. It's inefficient in that regard.

The XP-G has a larger hotspot although slightly less bright and has less spill as more of it's output is hitting the reflector.

The overall appearance of the XP-G beam is a bigger hotspot and a more even transition to spill so (to me) it all seems more useful since there isn't that glaring distinction between hotspot and spill as in the XR-E.

The XR-E is better for pure throw otherwise the XP-G seems to have every advantage.

 

[radu1976]

By sidespill I was understanding the beam of a flashlight, the projection on a wall , if we eliminate the hotspot ; so all the light around the hotspot , which is less intense than the hotspot.

So , taken 2 x P60 drop-in modules , one with an XR-E R2 , another with an XP-G R5 inside , and one host , so that both emitters from the drop-ins will be driven equally hard .
Positioned at 1 m from a wall , the R2 emitter will throw 130-200 lux in the sidespill...the hotspot will probably be between 6,000 and 10,000 lux.
I know that the XP-G R5 will have a less intense - but larger , in the same time - hotspot BUT , what I would like to know is how bright its sidespill on the wall - at 1m - will be comparative to the sidespill of the R2 module : 30 % ? 50% ?
Sidespill...the area from the edge of the circle ...as around the hotspot it's clear that the beam is more intense.

Both emitters driven at the same current , 1 m from the wall, equal conditions.

 

[gcbryan]

The area will be the same, right, since that's largely determined by the diameter of the head. The intensity of the spill maybe 20% less with the XP-G.

I'm just guessing here. I don't have numbers. I have both lights but the XP-G isn't where I am at the moment for me to directly compare.

Keep in mind that the XP-G is also 20% or so more efficient than the XR-E so driving it at the same power it will output 20% or so more lumens.

To me, the visual impression that you get with a XP-G when lighting up your backyard is that you get much more light than with the XR-E. The XP-G also throws fairly well for midrange distances.

I think to get more specific than this you just have to go to the Cree site and look at the data sheets for each emitter.

If you are thinking about a certain light or thinking about a certain application I'll be glad to answer more questions if I can but I don't have any more specific numbers to add.

Also, just to be factually correct (in case it matters) putting two different drop-ins into a P60 wouldn't mean that they were driven the same since the drivers vary with each drop-in. I'm sure you know that however.

 

[old4570]

Well , what part of the side spill do you measure ?

outer edge XP-G R5
Light 1 , 90Lux
Light 2 , 100Lux
Light 3 , 115Lux

XR-E R2

Light 1 50 Lux
Light 2 , 140Lux
Light 3 , 145Lux

 

[radu1976]

I was considering the outer edge , indeed.
I can see your results are quite redundant , we will probably need 2 modules which to be driven at the same current . I would assume that the XP-G sidespill would be brighter though.

 

[gcbryan]

I was considering the outer edge , indeed.
I can see your results are quite redundant , we will probably need 2 modules which to be driven at the same current . I would assume that the XP-G sidespill would be brighter though.

Why would you assume that? The beam angle of the XR-E is 90 degrees. The beam angle of the XP-G is 125 degrees. More of the beam from the XP-G is hitting the reflector. Spill comes from that portion of the beam not hitting the reflector.