How might it perform? Similar XM-L different size reflector

[nickdolin]

Seeing that I just ordered a new drop-in for my P20C2 (Has the R5 in it now). I'm curious how two lights with similar emitters may perform (beam profile wise).

I own a P-Rocket with the Xm-L Neutral tint T5. The reflector on this light isn't very deep but deeper than the P20 and a larger diameter.

The P20C2 has a more narrow (diameter at the bezel and emitter) and shorter reflector. I'm curious how these may compare as I've ordered the Cool White T6 XM-L.

I'm thinking that since at the emitter the P20 reflector is more narrow it'll have a tighter hotspot and with a smaller diameter at the bezel a tighter but somewhat brighter spill. The P-Rocket's reflector doesn't fit right against the emitter thus I think allowing a larger hotspot and larger but dimmer spill.

This should pair well with the P-Rocket as it will offer me similar power (720 LED Lumens vs. 810) but with longer runtimes (2.1A vs. 2.8A in the P-Rocket) and a slightly more efficient LED T6 vs. T5. Also, the P20's form factor is smaller... it's thinner and about a half inch shorter with a smaller diameter head for easier pocket carry.

It's too bad they didn't offer a 5A tint bin XM-L because I would have been all over that. As the 3A on my P-Rocket is on the cool side of neutral for me and I didn't really want to take the R4 and/or Q4 routes.

Any input or thoughts?

 

[gcbryan]

The larger diameter reflector will have a smaller hotspot and will throw further. Spill should be about the same since spill is the light that doesn't hit the reflector.

 

[eagle]

i don't think so, the small diameter wil have small hotspot, and hegher diameter will be more light efficient

 

[jorn]

Small reflector will give a big hotspot (floody beam).
Big reflector will give a smaller, more focused beam (more throw).
The angle of the reflector walls will also play a role in shaping the beam, and determin the size of the spill area. Spill is the light that dont hit the reflector. A deep reflector will have a smaller spill area than a shallow reflector.

 

[nickdolin]

This is kinda the response I expected... as there doesn't seem to be a clear-cut method to determining beam profile by reflector. I guess I"ll see when the light comes in... thanks for the input!

 

[gcbryan]

It is pretty clear-cup. You'll see when the lights arrive. If the emitters are the same the larger diameter reflector will throw further (if both emitters are driven the same) and will have a smaller hotspot. The reflector that is deeper will have a bit less spill. That portion of the beam will now go to the corona.

 

[orbital]

i don't think so, the small diameter wil have small hotspot, and hegher diameter will be more light efficient

Would you care to reword your first CPF post.

put it this way;
if what your saying is,, 'a smaller reflector will give tighter spot', you couldn't be more wrong.

 

[tre]

This is kinda the response I expected... as there doesn't seem to be a clear-cut method to determining beam profile by reflector.

It is clear cut. Some info above is just plain wrong while other info is right on the money.

I've tried different reflectors in the same light and same emitter just goofing around and measuring lux values (beam intensity or throw).

I've found that a larger diameter reflector gets you a smaller more intense hotspot with more throw. This is also true in every production light I own.
A narrow reflector gets you a larger less intense hotspot with less throw.

Now depth has more of an effect on spill (not the hotspot). A shallow depth reflector will have a wider spill area while a deep reflector will have a narrow spill area.



For example, a narrow deep reflector will have a wide floody hotspot with very little spill.

 

[nickdolin]

Got the drop-in (in) today and I'm pleased to report that the increase in light from the R5 is significant in both throw and spill (especially in terms of spill). Overall the flood is tighter due to the smaller diameter but the hotspot is just a touch larger but seemingly just as intense (could be cool vs. neutral light) as the P-Rocket... could be fresher cells in the ET than the P-Rocket. The tighter and brighter flood makes it look very bright vs. the wider flood of the P-Rocket. Due to the high draw of these lights and the costs of CR123's.... I've ordered a protected 18650 for the P-Rocket and an 17670 for the ET (even if I get a 5-7% loss in light with similar run times).