My SF L1 Experiment...

[RichS]

So, I got one of the new Cree L1's about a year ago, and have always loved this light. It has an awesome form factor, great build quality, excellent throw, grippy knurling, perfect UI.

However, for an indoor use/general purpose light or even for use when night hiking it leaves a lot to be desired. It's beam profile is mostly a big strong spot, with very little spill. I like this light a lot and wanted to mod it to be more of a multi-purpose light, so I asked Mudman CJ to put a warm tint LED and a reflector in it.

In our discussions, he indicated that although not driven very hard, you get a lot of output in this light due to the efficient optic - good point. So...why not keep the optic and just add diffusion film? But I did not want a pure spill light (I can use my F04 for that). So what if we just use a diffuser ring with a hole in the middle??

Thus my L1 experiment...

Note: CJ provided rough-cut samples of diffuser film for me to test. If I decide to go with this, he'll use a press and a punch at work for more even and smooth cut. Also, CJ will install the film on the inside of the lens if I decide to go this route. I just placed it temporarily on the surface of the lens for this experiement.

Stock L1, diffuser film full coverage and ring, F04 beam diffuser

L1 stock optic / diffuser film ring installed

diffuser film full coverage installed (left) / F04 beam diffuser installed (right)

L1 stock optic (left) / diffuser film ring installed (right)

diffuser film full coverage installed (left) / F04 beam diffuser installed (right)

L1 stock optic (left) / diffuser film ring installed (right)

diffuser film full coverage installed (left) / F04 beam diffuser installed (right)

Cycle: Stock optic -> diffuser ring -> diffuser full -> F04 beam diffuser

My conclusion is that the diffuser ring is a great alternative to eliminating the optic and going to a reflector for a more multi-purpose beam. Although you definitely lose some thow and a little overall output, it is far less than is lost with either diffuser, and the beam is much more friendly overall in my opinion. And the great thing is - it's easily reversable!

Now CJ can put a Q3 5A in this and make it all the better!

-Rich

 

[mikes1]

What a great post very nice pictures and useful information

Well done

Mike

 

[Sgt. LED]

Now what would happen if you took some 2000 grit sandpaper and carefully sanded a ring onto the optic?

 

[gallonoffuel]

Interesting. Thanks for the pictures. I have been toying with the idea of frosting the outer diameter of the lens in my EDC 6P. I use the glass frosting cream you can buy at local craft shops to diffuse glass lenses for certain tasks. Using a small adhesive dot (like they use to price items are garage sales, etc) in the center, I could mask off the center and maintain my hotspot, but diffuse the rest of the beam. I always wondered what this would look like.

 

[RichS]

Now what would happen if you took some 2000 grit sandpaper and carefully sanded a ring onto the optic?

Thanks Mike.

Sgt. LED - You're kidding, right?? First of all, with my artistic talent I'd have a freakin' mess of an optic once I was done. But more importantly, that would not be reversible like this will be. Who knows, in the future I may decide to use different light (Novatac) for general purpose and leave the L1 to more medium/long range outdoor duty. Then I'd just remove the film and be good to go again.

 

[Patriot]

Nice work. If I'm understanding correctly the ring mod give a smoother and brighter corona while lot costing you much in the area of throw. While not a nearly a diffused beam, it's an improvement without having to carry a separate piece around with you.

 

[mudman cj]

I have to give props to Rich for this idea. I suggested the use of diffuser film with the stock optic to take advantage of the greater efficiency of the optic whilst also not requiring the purchase of a $20+ reflector, but it was Rich's idea to try the ring.

Rich - I will see for myself soon enough, but for the other interested members, do you think the pics of the stuffed animal accurately portray the extent to which the ring of diffuser material attenuates the hotspot? It is hard to see much difference in the white wall shot, but the other shot looks like a significant loss of throw without much gain in corona/spill. I suspect that the gain in corona/spill would be more noticeable at closer distances, such as when using the light to illuminate your path while walking. Do you think that is true?

 

[Owen]

Awesome stuff. CJ did a Q3-5A/McR19XR reflector mod on my L1. The improvement in beam quality, and the usefulness of the beam profile, along with the much better tint makes it such a better flashlight.
Had the same mod, except with a Q4-5B done on my E2L, and have only had it back a few days. I have LDF over the entire inside of the lens right now. Neutral tint and flood is where it's at for me most of the time.
I had put LDF on the outside of the lens of the stock light to try, but the beam looked like crap compared to having it inside(hotspot somehow had a hole in it, and the whole thing looked uneven). Yours looks much better???

I do like the way the LDF gives a semblance of a hotspot, unlike the F04, and FM34 for the C-series. Have a UCL/LDF lens for 6P,etc. that I've used with several dropins, including a 5 mode R2, Dereelight 3SM 5A, and a Malkoff M60W.
Magnificent beam for any kind of close use, and general utility.
My beamshots aren't so great, but I posted a thread about the E2L here:
http://www.candlepowerforums.com/vb/showthread.php?p=2992637#post2992637
Last post has it with the LDF.

 

[DHart]

Interesting mod... that diffuser ring really does a nice job with the L1 optic!

This talk about CJ and the Q3 5A/reflector mod has me pondering... hmmm. Who is CJ, where can he be reached, and what does he charge for such a modification? :thinking:

 

[Owen]

mudman cj-post before my last one.

 

[DHart]

mudman cj-post before my last one.

Ooops... I wasn't paying enough attention! Thank you Owen.

 

[RichS]

Rich - I will see for myself soon enough, but for the other interested members, do you think the pics of the stuffed animal accurately portray the extent to which the ring of diffuser material attenuates the hotspot? It is hard to see much difference in the white wall shot, but the other shot looks like a significant loss of throw without much gain in corona/spill. I suspect that the gain in corona/spill would be more noticeable at closer distances, such as when using the light to illuminate your path while walking. Do you think that is true?

I'll agree with you - by the pics I really was surprised to see how much the ring of diffuser material affected the hotspot. But, the spill really was more visible than in the pics to my eye. The effect in real life was a much more pleasing beam to use around the house, and you can see by the other pics where the full diffuser was used, it does retain a lot more of the hotspot than it would have otherwise.

The only downside is I didn't get it outside to get the true effect outdoors. It might be a different story. Now the only question in my mind is: Will this solution give me more throw w/ some sidespill than if I went with a reflector. What do you think? If the reflector will end up giving me more throw than this optic with diffuser film, I'd rather go with that - even for the extra cost. I wish I could compare the two side by side....

 

[RichS]

Nice work. If I'm understanding correctly the ring mod give a smoother and brighter corona while lot costing you much in the area of throw. While not a nearly a diffused beam, it's an improvement without having to carry a separate piece around with you.

Thanks. Yep - that was the intention. I really didn't like my L1 with the F04 installed, and taking it on and off for varying use is a pain. I'd rather use low/high as needed for range with a more multi-purpose beam.

 

[mudman cj]

The only downside is I didn't get it outside to get the true effect outdoors. It might be a different story. Now the only question in my mind is: Will this solution give me more throw w/ some sidespill than if I went with a reflector. What do you think? If the reflector will end up giving me more throw than this optic with diffuser film, I'd rather go with that - even for the extra cost. I wish I could compare the two side by side....

Well, when your light gets here I will be able to make direct comparisons - after I mod yours to a Q3 5A like mine. It wouldn't be fair otherwise. Looks like I will have to take some pics and post them here for you to see.

 

[RichS]

Well, when your light gets here I will be able to make direct comparisons - after I mod yours to a Q3 5A like mine. It wouldn't be fair otherwise. Looks like I will have to take some pics and post them here for you to see.

Awesome - I'd forgotten about that! I'm real anxious to see how the optic fairs against the McR19XR.

 

[mudman cj]

Here are some beamshots comparing the stock L1 with cool white LED to a KX2 with Q3 5A and the McR-19XR reflector. The KX2 was powered by 2 Surefire primary cells and the L1 with one Surefire primary cell. These first shots were setup with the lights 4.5 feet from the wall. The L1 is on the left. The upper pic shows the stock optic and the pic below has the ring of LDF (light diffusion film) added.

And now here are the same shots with the exposure set to -2eV:

The next two shots were taken with the lights 22.5 feet from the wall to give a better indication of throw. Again, the upper pic is with the stock L1 and the lower pic has the addition of the LDF ring.

I plan to swap the cool white LED in the L1 to a neutral white emitter and take some more beamshots, but I am visiting family this weekend so it will be a while before that happens.

 

[RichS]

Very telling beamshots C.J. - thanks for doing this. Your shots indicate in a much more obvious way that the ring of diffusion film cuts down on throw too much without enough of a gain in spill to make it worthwhile. I personally do like the beam pattern of the diffusion film vs. the F04 however, but the ability to easily remove the F04 makes it a much more practical option.

I think this was a worthwhile experiment with a clear answer thanks to C.J.'s input. What I thought might happen, is that the very center of the hotspot would retain full brightness, but that it would be a smaller hotspot due to the ring of diffusion film. This demonstrates that the entire surface of the optic contributes to the entire hotspot.

Since I'm having C.J. mod with a warm tint, it will be even more useful outdoors, which makes me want to now leave the optic in place to give me the most throw. I initially wanted to use a reflector for a more well-rounded beam, but in reality I have other lights such as Novatacs for this. This L1 will make a nice, throwy light for outdoors.

 

[mudman cj]

It's too bad we couldn't find a magic shortcut to increase spill without loosing much throw, but I knew this was a long shot given the amount of spill area compared to hotspot area. It just takes a lot of light from the hotspot to make a noticeable increase in the spill because it is spread out over so much area. The reflector also sacrifices throw for spill, but notice that the hotspot size is also smaller with the reflector than with the optic. I have really come to appreciate a larger hotspot for lights that are intended to be used at what I call 'medium' range. Pencil beam lights can still have too small of a hotspot to be useful at 'medium' range, and Surefire is certainly not unaware of this. They have designed their lights to be useful, not to post the highest lux readings.

I think the neutral tint mod will increase the utility of the light nonetheless. You will still appreciate the warm tint even at longer distances, especially outdoors. But now you need to have the Novatac modded with a warmer tint.

 

[gottawearshades]

Very interesting, Rich!