Loss of light output in M-series bezels....

Some of you may remember the thread I started here......SF's M2 bezel + E-series adapter kit I have two technical questions relating to that thread, for those of you who are familiar with SureFire's M-series and C-series bezels........
I noticed in my M2 bezel that the lamp module is recessed about 1/2 inch from the lens, due to the shock mount gasket in the bezel. In the thread above, I stated that I had acquired a P91 lamp module, to give the bezel the highest output lamp available for it using my E1e body and my two Dspeck battery extensions. When I compare my G2/P60 lamp module to the M2/P91 module, I of course see a different light output level, and I see a much smaller overall light pattern projected from the M2.

My first question is, if the overall diameter of the M2 bezel's output is so much less than that of the G2, then about how much of the P91's light output is lost through absorption into the gasket material? I am aware that the C-series bezels do not have the gasket material, and no light from any lamp module will be lost inside the bezel since the module's reflector is flush against the Pyrex glass lens.

My second question is can I remove the shock mount gasket from the M2 bezel, and use the bezel with the P60 or P91 module in order to regain the lost light output?

I've noticed the same loss of visible output in my M2/P61 /ubbthreads/images/graemlins/frown.gif

I think the P90/P91 has the same diameter reflector as the P60/P61 lamps. Not sure how much light output is lost though.

I don't think you can remove the gasket (unless you can remove the pyrex lens).

The M series is for those who care more for reliability and ruggedness than a few percent of output I guess...
If you won't be dropping or whacking things with your light, then the regular C2/C3 bezel should be best for you /ubbthreads/images/graemlins/icon3.gif

mokona2,
There is a retaining ring holding the lens to the bezel. I am sure that the gasket can be removed after removing the lens out the front. But what about the fact that the module will be sitting 1/2" closer to the lens than before? Batteries don't stretch 1/2".........do they???

kongfuchicken,
I am aware that the C2/C3 bezels would have been better suited for my needs. But as I stated, the M2 bezel/P60 lamp module/adapter for E-series bodies, were gifts. If I hadn't received these items, this project would have never started in the first place. Therefore, I will not be acquiring a C-series bezel. I would gladly trade the added ruggedness and reliability of the bezel, for a C-series layout. I will just have to work with my current parts and try to make it happen to my satisfaction. If it is impossible to do, I will have to adjust my behavior to press the rubber button on the tailcap "sparingly."

Upon looking long and hard at the reflector's depth in the bezel, I strongly believe that the loss of light is not just a few measly percentage points. Look at how far the reflector is from the lens, and look at how much surface area is dedicated to light absorbing gasket material.

Thanks guys.

Lux,
pm sent.

I just did an experiment! I compared my M2 with a P60 module and a two cell body configuration, with a stock G2. The M2 had a smaller footprint, with less sidespill. The overall light output looks the same to me. May I assume that either the loss in sidespill is an unrecoverable one due to absorption by the gasket material, or that more light is transferred into the hotspot portion of the beam pattern?

Doesn't anybody own an M2 bezel and a C2 bezel or G2 light?

I assume the gasket is absorbing it

Yes, and IMO the difference is minimal and not really noticeable. Honestly I prefer the M2 bezel because of the Shock Isolation and don't find that I need that extra 1 or 2% in the sidespill. Maybe this is just because I'm more of a throw type of guy. I also suspect that the output loss is less than we think because most of the "light" of the beam is in the hotspot and not the outer edge of the sidespill. The only time there is anything even minimally noticeably different is during a "white wall test."

-Mike

M2 on left C2 on right. Both lights were held at the same distance from wall.
The M2's hotspot wasn't larger; I moved the camera a bit...
Not very well shown but there was 30 to 40% of spill missing with the M2.

Garageboy,
I agree with you. There is no other internal material in the path of the emitted light on the way to the lens.

Mike,
The 1% or 2% loss is nothing as far as I am concerned. Agreed on the perception of loss due to the majority of the light residing in the hotspot. The image of kongfuchicken shows that there is the same general light intensity in the sidespill areas of both lights, although they differ in size.

Li,
Your image confirms what I have seen when comparing my M2/P60 with my G2/P60. I have many lights that excel in sidespill, so it would not make any sense for me to entertain any thoughts of selling/trading the M2 bezel. Do you agree?

Thank you for your input, all. I had to submit a "emergency post" this morning to draw attention to this thread. It worked!

lux, if I were you'd keep it. The loss of spill wasn't all that noticeable in most uses but in one of these situations usually followed by a loud "Darn it!", the M2 bezel can save the day.
As a good flashaholic, I'm sure you have more lights than you need anyway. /ubbthreads/images/graemlins/grin.gif

Li,
Words of wisdom, indeed. Confucius could not have said it better himself! I'll keep the bezel for those loud "Darn it" situations. I pity the fool who will be in the line of sight of my M2 bezel armed with the P91 lamp module......

Your bulb will thank you when you accidentaly drop it =D

[ QUOTE ]
GarageBoy said:
Your bulb will thank you when you accidentaly drop it =D

[/ QUOTE ]

True, but only if you drop it juussst right /ubbthreads/images/graemlins/icon3.gif

Garageboy & mokona2,
It took two resourceful guys like you to make me realize that shock mounting in the M2 will come in handy for more than weapon use. I have dropped a few of my lights and other delicate objects, wishing that I hadn't because they broke or somehow got "tweaked." Your comments have made me decide to keep the M2 "for all posterity." Consider that when we drop, throw, run over, or step on Luxeon based lights, we don't have to worry about such "silly" things!!! Now this is something to ponder, indeed......