Collimation Experimentation... -> beamshots added

I'm sure that many of the regular readers here are familiar with my disdain for the NX05 (new style) collimating optic.

What really turns me off about the NX05 is it's TINY bright hotspot at the beam's center, and a ton of peripheral light spill that's too wide (and dim) for my use.

What I prefer is a beam that has a much larger, more evenly dispersed hotspot with an overall tighter dispersion.. Tighter sidespill would be brighter and more useable.

I decided to see what I could do with an NX05 by filing off a little. I found that I could widen the hotspot considerably by taking material off of the base of the collimator, like the one on the left in the photo below:



When filing, care must be taken not to go too deep. At the end of the collimator's pocket (where the LED fits in) is a dome shaped protrusion. This dome is clearly visible in the photo as the "dark dome" in the pocket. I like to file off enough where the dome of the Luxeon is just about to touch the dome in the collimator. I've gotten some nice beams by cutting the collimator in this fashion.

Best of all, it also serves to smooth out the "grill shaped" defects from the colored Luxeons. Anyone who's not real thrilled about the NX05 in stock form, really should give this a try to one of their collimators.. <img border="0" title="" alt="/ubbthreads/images/graemlins/cool.gif" src="images/icons/cool.gif" />

I feel like I've solved fully half of my dissatisfaction with the NX05 as I've managed to widen the hotspot. But the overall dispersion still remains the same (although brighter and more usable).

I'll see if I can put together a beam shot of 2 identicle Luxeons (yeah, right <img border="0" alt="/ubbthreads/images/graemlins/icon15.gif" title="" src="graemlins/icon15.gif" /> ) using the cut and un-cut collimators for comparison....

stay tuned.. <img border="0" title="" alt="[Big Grin]" src="images/icons/grin.gif" />

Re: Collimation Experimentation... -> beamshots added

looks great!

any info you might have on how to do this would be appreciated

Re: Collimation Experimentation... -> beamshots added

Slick,

Staying tuned...

You know, I think it helps to consider the collimator as two lens elements; a ball and then tube. The ball is a convex/plano lens and consists of the interior ball you have elluded to as well as the flat surface on the front of the collimator. I believe that this ball element processes all of the light that hits it directly from the LED. The tube I believe catches the side spill and with internal reflection sends this light out the front as well. The light is reflected internally because the angle of incidence of the light hitting the outside surface (once inside the acrylic) is greater than the critical angle and can't excape. I believe you have stated that you prefer the old style optic and I think the big difference here was the ball portion was a convex/convex lens. My understanding and explaination of the collimator could be all wet and it would be great if someone would clarify this for us dummies!

From the description of the beam you prefer, have you tried an Ex reflector with a SE yet?

- Don

Re: Collimation Experimentation... -> beamshots added

Roth - I use a fine-cut mill file layed flat on my workbench. I then draw the collimator's backside across the file surface in successive strokes, rotating the collimator a few degrees with each stroke.

The key is in using a file that's fine enough so it doesn't easily "grab" the collimator from your grasp. Damage from even the smallest screw ups stand out like sore thumbs (which I also have..).

Don - Thanks for that expanation, this is making even more sense now. One other thing the old style optic had was a parabolic angle on the side. I'm pretty sure that this in conjunction with the convex front cavity combined to make that beam. I really like the NX01 beam a lot, so it's been difficult trying to wean myself away from it.

I'll post the beam shots in a couple of hours. I have already built a red and a red/orange mod today and my fingers & thumb are very sore and on a Heineken drip at the moment..

I have another red/orange that I can finish out and assemble with an un-modified optic. Hopefully, red/orange will make a beam shot that shows up the difference well.

Re: Collimation Experimentation... -> beamshots added

Don,

Your explanation would explain why my shortened one is dimmer! Damn point on the live center on the lathe gorked the center of the "ball" about .040" diameter and .035" deep. Now I gotta wait until the 6th to try it again with a little more careful set-up. (grrrrrr)

Larry

Re: Collimation Experimentation... -> beamshots added

Originally posted by tvodrd:
Don,

Your explanation would explain why my shortened one is dimmer

Click to expand...

<font size="2" face="Verdana, Arial">Larry - your shorter collimator isn't *really* dimmer... The light that was all once concentrated into the very center has now been spread out.. So while the center may lux dimmer, the outer areas will lux higher.

Re: Collimation Experimentation... -> beamshots added

Slick,

Awaiting your beam shots with baited breath......

Re: Collimation Experimentation... -> beamshots added

Slick,

Just trying to add to the knowledge base here -The overall beam size and shape seemed to be the same, including the center hotter spot. This was while fumbling the two optics back and forth and shining it at the wall in a dark bedroom. The shortened one was definately dimmer, I think due to the amount of light it threw towards the rear vs almost none for the stock optic. Again, I shortened mine from the front.

Larry

Re: Collimation Experimentation... -> beamshots added

Slick,

Looks interesting...I'm glad there are guys like you experimenting to find out what works and what doesn't. Thanks for the info - staying tuned...

I believe my Lambda Illuminator w/NX05 has the same beam profile you've described. It's not an SE or HD, so do you think your collimator mod would yield similar results?

I've gotten sore fingers many times doing things like this by hand, and I've learned some tricks along the way, so I thought I'd share one that might work for this.

For trimming or routing small parts that are really too small to handle safely, I've used two-sided tape (the thin stuff) to attach the workpiece to a larger piece. This has worked quite well for me in the past.

I wonder if one could attach the flat face of the collimator to the squared end of a large wooden dowell (or anything really)with the 2S tape, and trim it using a good miter slide or table slider on the table saw using carbide tipped blade(if sharp, cuts polycarbonates and acrylics nicely).
My table saw setup is good enough to "sneak up" on a dimension for an exacting fit.

I've done similar trim jobs on small parts like this before, and as long as I don't try to make a heavy cut, the tape holds well. If the tape holds too well making separation difficult, just warm things up a bit with sunlight or a lamp, and the adhesive should soften a little.

Hope this helps - John

[EDIT: This carpet tape trick might also work in the drill press or lathe if you can get the collimator centered on a suitable piece of round stock]

Re: Collimation Experimentation... -> beamshots added

Lambda - I've been trying a few diffent beam shotz and they all wind up looking identical!! The red/orange is so bright that they simply overwhelm the camera... Also working against me is the fact that this is an old Mavica that's not even 1/2 megapixel.

I think I might try setting up the flashlights to run on 1 battery or something to get brightness down to a level that I can capture in a photo to share.. Trying again in a few minutes..

Larry - Please contribute all you know! my mistake... I had assumed (I know..) that your collimator was shortened from the back like mine. I could certainly see how a frontal reduction (lobatomy ) might dim output. Alternatively, maybe you could fix your mod by trying one shortened from the back? Unless, if part of the reason it was shortened from the front was also to reduce diameter.

Illuminated - Thanks for the tips. I do attach small work pieces to larger ones for easier handling often times, but most of my problem has been the sheer number of pieces I've worked on today. I've also found that a pair of "sparkplug cable pliers" works very well for holding small parts securely without damaging them..
*************

Alright.. I'm off to find a way to dim these lights enough to show the beams without "blinding" the camera........

Re: Collimation Experimentation... -> beamshots added

Table saw method ought to be great for several collimators at a time if attached to the squared edge of a suitable board...

John

Re: Collimation Experimentation... -> beamshots added

Most interesting topic.

Slick, I've also grown increasingly dissatisfied with the NX-05 beam in the past few days for exactly the same reasons you stated.

Do you know of any comparo photo of the NX05 and NX01 beam side by side?

Thanks,
MO

Re: Collimation Experimentation... -> beamshots added

Originally posted by moses:

Do you know of any comparo photo of the NX05 and NX01 beam side by side?

Thanks,
MO

Click to expand...

<font size="2" face="Verdana, Arial">Since these mods are 2AA / red/orange Luxeons, I am going to try swapping the lithium batteries for NiMh's to get them dim enough to photograph...... AND - I just so happen to have another red/orange mod that I built using an NX01, so I'll try and get both.. Any yeah, NX01 Optics were never intended for use on Lambertian emitters..but I've never let things like that stop me

Re: Collimation Experimentation... -> beamshots added

you think you have a sore thumb?!


sanded the top of my thumb off in a disc sander in shop class 10th grade...luckily, after a couple surgeries it grew back!
hey...i just got the digi-cam today...i have been anxious to use it

i'll have to try to mod some of my optics...i'm not very fond of the standard ones either (actually, i'm pretty much not-fond of anything that is standard.)

Re: Collimation Experimentation... -> beamshots added

Alright, this is the best that I could do...

Fresh NiMh's were still too bright, so I used DEAD NiMh's that measured 1.10 - 1.11v I checked to make sure the cells were matched for both flashlights to keep them even.

The contenders are both Mini-Mags w/ram tailcap switches using red/orange lambertian Luxeon emitters from the same reel.



The ONLY difference is the silver/red flashlight on the left is using the cut-down collimator that is pictured in the photos in my initial post. The black flashlight is using a collimator that is un-modified (except for "nub" removal).

The photo below shows the modified collimator - also on the left... It was very difficult to get anything that approached showing the differences between these two beams. All I can say is that the beam on the left is MUCH shoother and more even than the beam produced by the un-modified collimator on the right...



For $2.50 you gotta try one.......

Re: Collimation Experimentation... -> beamshots added

Nice...looks promising, staying tuned...

John

Re: Collimation Experimentation... -> beamshots added

Roth - Dang man, that hurts just looking at it... I used to do a lot of woodworking - notice I said "USED TO". After waiting 8 months for the end of a finger grow back I decided it was time for a new career in computers.

moses - I didn't forget your request for a beam shot of a NX05 vs. a NX01

In the photo below, the NX05 is on the left, and the old style NX01 is on the right.. This is why I like the NX01 better. I tend to think of the NX01 as a fatter hotspot - OR a "tighter flood". You can draw your own conclusions, as the photo (while poor) generally depicts the differences between these 2 beams.

Both flashlights have good batteries in this photo.

Re: Collimation Experimentation... -> beamshots added

Very illuminating Slick! Thanks!

- Don

Re: Collimation Experimentation... -> beamshots added

Slick, THANKS for your obvious time invested to answer our questions. MUCH appreciated.

Yes, the NX1 seem to be more even in a larger hotspot. Your NX05 seems very usable huge spot but obviously in real life, the side spill is very weak and not very usable. So, I wish I could try a NX01.

Is the NX01's physical dimension virtually same as the NX05?

Query to all: Anyone knows WHO makes the NX05? They probably makes the NX01 also and having done the acrylic 'mold' (I presume) already, it is trivial for them to make another run of a few hundred. Problem is finding out who makes them. My take is that at least one person on this board knows but isn't telling - don't remember who.

Again Slick, THANKS!
Thanks,
MO

Re: Collimation Experimentation... -> beamshots added

Slick,

Are you primarily using HD's and do you feel the old optics are better with the low domes as well? If I'm not mistaken, the NX05 was designed as an improvement for the low dome and Lumileds hasn't addressed the HD's or SE's with any secondary optic program. Am I correct on this?

- Don