ReFocussing the Fenix L1D-CE (& L2Dce)

[UnknownVT]

The bezel/reflector part of the head unscrews on the Fenix L1D-CE (L2D-CE has the same head)
(use rubber bands or gloves for grip)-

and by unscrewing the bezel one can actually focus the beam -
this can minimize the infamous Cree dark halo ring.

Ref: please see -
Bezel/Reflector part of head unscrews Post #39
Beam focus by unscrewing bezel/reflector part of head - in Post #68
in Fenix L1D-CE Comparison Review

However it was pointed out in another thread that doing this puts the LED slightly BEHIND the reflector - with possibly attendant loss of light.

This may well be true - but HOW MUCH?

I was curious to know - but I do not have light measuring equipment, and although figures/measurements do tell us a lot - they alone canNOT tell everything.

The best is still eyeballing and a "look-see" - on the surface not very "scientific" -
but isn't this how we use and see things?

So I did the next best thing - I took Before and After beamshots of the Fenix L1D-CE with the reflector as delivered - ie: "Stock", then ReFocussed the beam to try to get the best without dark halo ring (I unscrewed the bezel/reflector until the dark halo just disappeared.)

These beamshots used the exact same exposure settings for each respective pair of before and after shots, I did a full exposure, and one at the usual -2 Stops Underexposed.

Then I cropped the After photo and flipped it horizontally and merged it with the Before photo - so I got a side-by-side direct comparison of before and after.

These two beams in the composite merged photos should be directly comparable and should show any difference in brightness - within reason - ie: probably as well as the eyes can detect - possibly a bit better.

Before vs. After composite beamshots -

Just to be sure I also took comparison beamshots with a reference control light of similar brightness level - the Fenix P1D-CE primary CR123A on Medium -

Before control reference comparison with Fenix P1D-CE Medium

After control reference comparison with Fenix P1D-CE Medium

I leave it up to you to draw your own conclusions from the beamshots I have presented -
without any influence from my comments, for now.

Part 2 - ReFocussing the Fenix L2D-CE - Post #18

 

[adirondackdestroyer]

Re: ReFocussing the Fenix L1D-CE

I tried this but it doesn't work very well with mine because the emitter is off center. Mine has a dark half circle on one side of the hotspot but not on the other. It kind of bothers me because I know that throw is really decreased since mine isn't centered. The throw on mine isn't a whole lot more than an L1P.

 

[UnknownVT]

Re: ReFocussing the Fenix L1D-CE

adirondackdestroyer wrote: "I tried this but it doesn't work very well with mine because the emitter is off center.
It kind of bothers me because I know that throw is really decreased since mine isn't centered. The throw on mine isn't a whole lot more than an L1P."

Ouch! - so sorry to hear about your sample.
I hope Fenix doesn't have a problem with centering the LED.

Although I think it's pretty well known that focussing any light is dependent on how well the light source is centered - so this isn't unique to the L1D-CE.

Just an additional comment - obviously as long as the LED is reasonably well centered - the L1D(L2D)-CE can be focussed with reasonably good precision as the threads are pretty fine, also the O-ring is thick which means the position is can be held/kept pretty well without having to resort to any LocTite or glues

 

[Schizoid1]

Re: ReFocussing the Fenix L1D-CE

Mine is a little loose. Which of the LocTites or other glues are good to get the head to stay put once you get it focused? I checked the store but there were 3 or 4 versions of LocTite - A gel, an extra strength, and one with a separate activator tube. Thanks!

 

[Quantumstate]

Re: ReFocussing the Fenix L1D-CE

There are two basic kinds of Loctite: red and blue. Red locks it forever. Blue is undoable, with a little effort.

Unknown, I honor your work.

But what is the purpose of defocusing? Is it To spread the beam, or is it to deemphasize the dark corona? To me, there is no dark corona with this flashlight, it just appears so because there's such a sharp difference in light it fools the eye.

If it's to spread the hot spot, I'm starting another thread on the L0D CE for beam mod with a concave lens, to make a flood.

 

[curtis22]

Re: ReFocussing the Fenix L1D-CE

There are two basic kinds of Loctite: red and blue. Red locks it forever. Blue is undoable, with a little effort.

Fenix must have used red Loctite on my L2D.

 

[moontroll]

Re: ReFocussing the Fenix L1D-CE

Is it just me or does the refocus shot seem a little brighter with a hotter(smaller) spot.The beam looks nicer to,wonder how it effects throw.

 

[PB92]

Re: ReFocussing the Fenix L1D-CE

What's the logistics of centering the emitter?

 

[Hondo]

Re: ReFocussing the Fenix L1D-CE

Vincent,


Good job! I have done this too to my L1D & L2D. I thought I may be sacrificing a bit of center intensity, but comparisons before and after to other lights suggested that if it was hurting throw, it is by a margin a whole lot less than the increase in output from the Cree emitter. My LED's are not perfectly centered, either, but I stopped focussing when there was still just a tiny crescent of dark left on one side of the hotspot, over 90% of the original effect gone, and hard to find, even on the white wall.

Your shots make it look like it is even better than I thought, I see no loss of center intensity due to backing the emitter up in the reflector, some pairs even make it look hotter on center after re-focussing. Thanks!

Hondo

 

[ernsanada]

Re: ReFocussing the Fenix L1D-CE

My head is stuck on tight. Can't seem to move it.

For the folks who got their heads off, was it very hard to take off?

Were the head's glued on ?

 

[Hondo]

Re: ReFocussing the Fenix L1D-CE

I am sure there is thread locker in there, but I only unscrewed enough to achieve the desired results, as I wanted it to stay put when I was done (it does!). One of mine I just cranked with my bare hands, the other I had to put two #64 rubber bands wrapped round 3-4 times on each side of the head joint to give some more diameter and traction, then it came, but they were hard going for the whole ~1/2 turn out to where I have them now. Be carefull, but I have used on other tough jobs a piece of leather belt and pliers over the rubber bands, with no damage to the aluminum. Good luck!


Hondo

 

[WildChild]

Re: ReFocussing the Fenix L1D-CE

I used rubber gloves to do this! With bare hand I'm able to screw back the head but it's very difficult and I'm unable to unscrew it. With the gloves it's easier but still very hard to do! After it has unscrewed enough to remove the dark ring, I think it will be held in place well enough so switching mode will never move the reflector from its new position!

 

[yellow]

@ UnknownVT, this mod rocks!!

I only needed a broader rubber band around the middle part.
less than 1/4 turn of unscrewing and the beam is very nice now.

Compound on the head treads prevent these 2 parts from moving, when the head is turned later (normal/turbo mode)

 

[UnknownVT]

Re: ReFocussing the Fenix L1D-CE

Quantumstate wrote: "But what is the purpose of defocusing? Is it To spread the beam, or is it to deemphasize the dark corona? To me, there is no dark corona with this flashlight, it just appears so because there's such a sharp difference in light it fools the eye."

I see a dark halo/ring, and my beamshots show a dark halo/ring - albeit less emphasized compared to a P1Dce.

I have read, followed and partcipated in the huge controversy about the dark halo - and do understand that some of the cause may be an optical illusion.

But the fact is even when I'm told, and am convinced it may be an optical illusion, I can still see the dark halo/ring.

The REfocussing - and I emphasize RE- as opposed to DE- of the beam is an experiement to try to minimize the dark halo.

I can see both in the flesh and by my side-by-side comparison beamshots that this worked....

and part of the objective of this was to see if I could detect any loss of light - by eye and by beamshot .....

(I thought I stated all that in my opening post -
there were no other agendas - hidden or otherwise -
however, being an open forum -
I always hope some aspect I had not seen would be brought up by CPF)

 

[Quantumstate]

Re: ReFocussing the Fenix L1D-CE

Nobody thinks you have a hidden agenda. Just trying to help. I don't know what's been said about this in the past, so my suggestion had nothing to do with that.

It's just that I can't see a dark halo in your pictures on this end.

 

[UnknownVT]

Re: ReFocussing the Fenix L1D-CE

Quantumstate wrote: "I don't know what's been said about this in the past"

Hope these links help

Hot Spot halo

Fenix Engineers analyze the P1D CE's beam
(huge thread)

Fenix L1D-CE Comparison Review

 

[UnknownVT]

Re: ReFocussing the Fenix L1D-CE

ooops! sorry, inadvertant double post.....

 

[UnknownVT]

Part 2 - ReFocussing the Fenix L2D-CE

Same methodology as for the Fenix L1D-CE ReFocus as in opening post #1 (link) -

(oops! I boo-boo'd on the Underexposed shot - that's - 1 1/3 Stops Underexposed to try to best show the slight dark halo/ring of the before/stock vs. the After/ReFocussed - I've corrected the text and highlighted it in green on the beamshot)

Before control reference comparison with Fenix P1D-CE High

dark halo/ring is present but noticably less on the L2Dce (or L1Dce) than the P1Dce.

After control reference comparison with Fenix P1D-CE High

For the Full review of Fenix L2Dce please see -

Fenix L2D-CE Comparison Review

 

[fireboltr]

Re: ReFocussing the Fenix L1D-CE

there are actually 3 types of loctite
Blue can be broken free by hand with effort
Red can be broken free with a little heat and effort
Green (290) is pretty much there forever it takes alot more heat and effort than our lights can handle

dang i destroyed one head trying to break green free at almost 400 degrees!!!!


i forever for now on only use blue loctite on anything that i might want to ever come apart

 

[ernsanada]

Which Loctite does Fenix use?