View Full Version : Understanding lens degrees

06-21-2007, 11:04 PM
Hi all

It gets asked pretty much every day around here....

"Which degree lens should I use? What's the difference?"

Well, I'm here to help answer a few of your questions as well as dispel some of the myths you might have heard.

First off, we sell two different degree lenses here: 10 degree and 5 degree. Both work well with the standard 1" thick walled blades.
In fact, if you have a thin walled and a thick walled 1" OD blade under 30" in length, you probably won't notice much difference. It's
the longer blades and the 3/4" OD blades where you start to see one outshine the other. More on that below.

When you hear 5 degrees and 10 degrees, it's natural to think that those degrees are the angle at which the beam spreads. This is
true, but what most people do NOT realize is that a lens measures the angle that the beam spreads to ON EACH SIDE of center. That means that a 5 degree lens diverts from the center line 5 degrees on each side. That makes for a 10 degree beam, not 5 like many people assume. Same for a 10 degree lens. The beam for it is really 20 degrees.

So what does this mean to your average Luxeon saber builder? In the simplest terms, it just means that a 10 degree lens makes a fatter
beam than a 5 degree lens does. But which is better for YOU? Well, that depends on which blade you're intending on using the most. If you can visualize that the 10 degree's beam is twice as "fat" as a 5 degree, then it helps you to understand why a short thin walled blade (which has a larger internal diameter) would light up a little better with a 10 degree whereas the 5 degree would be better suited for a longer thin walled blade or a thick walled blade, which has a tighter internal diameter.
Likewise, if you are using a thin walled 3/4" OD blade, which are popular to many because of their light weight, then it makes sense that the smaller internal diameter would benefit from the tighter degree beam the 5 degree lens offers. This is only good to a point though. As with any blade, once you get so far away from the light source, the blade will dim out to the point of being too dark. Fortunately, most people don't use 4 or 5 foot blades, so it becomes a question excessive length versus even brightness.

Here is a comparison picture I took a few years ago showing how the same LED lights up the same blade differently depending on which degree lens is used. Note: I used a 6 degree lens at the time, but they are darn near identical to the 5 degree ones we now sell. The blade is a 36" thick walled model with only a single wrap of blade film. Double wraps provide more even lighting, but this shows the difference between the various lenses better. I tested a few other degree lenses at the time too:


This is a picture of a 3/4" thin walled 34" long blade using a 5 degree lens. Again, it uses a single wrap of blade film:


Now for those pesky myths you might have heard:

MYTH # 1: You don't need a lens. The LED is bright enough as is. I hear they're like a laser.

Not true. While Luxeons are VERY bright, they are not a laser and need focusing. Without a lens, the brightness cannot be focused into the blade efficiently. Bottom line: You need a lens.

MYTH # 2: All lenses are the same.

Again, not true. There are several different degrees of lenses built, but only a couple really work well for the Luxeon blades TCSS sells.

MYTH # 3: The tighter the degree, the brighter the blade.

As the previous paragraphs have said, certain blades, like a thin walled 1" OD model works better with a 10 degree. Once the blade gets over 30 to 35 inches however, you might want to consider a 5 degree to have the blade light up more evenly. You will lose base flare to some degree by switching to a 5 degree lens however, so if you like that look, you might be better with a 10 degree and limit your blade length to 3 feet or under. "Base flare" is the phenominon where the point of the blade closest to the saber is so bright, it seems to "flare" out and can actually look wider, especially in pictures.

So to recap:

1" thick walled - Generally use a 5 degree lens. A 10 degree will give more base flare if you like that look, but will not light as evenly.
1" thin walled - If under 35 inches long, use a 10 degree lens. If longer, a 5 degree might be better for you.
3/4" thin walled - Pretty much a 5 degree lens all the time. A 10 would be OK for an extremely short blade, but a 5 would be better.

I hope this helps.

06-22-2007, 05:22 AM
well said, i use a 5 degree in my 32" thick walled blade and my eyes cant even perceive the dim spot. it shots up with a camera, but just barely

06-23-2007, 10:19 AM
nice, wonderful writeup, thanks Corbin!

Hasid Lafre
06-23-2007, 10:25 AM
Hay corbin you think this could do more if it was in the new to sabers sections?

06-24-2007, 05:14 PM
Hay corbin you think this could do more if it was in the new to sabers sections?

Actually, I already integrated it into the LED section there with an included link to this thread if people want more info.

10-20-2007, 06:24 PM
thankx corbin.... now i dont have to spend time weeding through all the posts to find the answer to that q's i was about to ask!

10-20-2007, 08:19 PM
thankx corbin.... now i dont have to spend time weeding through all the posts to find the answer to that q's i was about to ask!

No problem Orko. Glad to help. That's what we all contribute to the forum for. Like many others before you, I suspect after you've been around here a while and made a few sabers, someone new to the scene will look to something YOU might have posted for information.


10-23-2007, 08:19 AM
I was curious if anyone has seen what ultra uses, its basically just a chrome housing like from a maglite. Does anyone know if its any better than an optic or just a different way of doing it? I used one of their luke conversion kits [sorry tim] for Ryu-Kenjushi's rotj saber and noticed there was no actual optic. It seems to look just as good.

10-23-2007, 09:53 AM
They are reflectors. They're available in 17, 20 and 27mm diameters. A couple years ago I posted a comparison pic of the optics vs. the reflectors:


Personally, I don't see a ton of difference between them. I tend to go with 5 degree optics myself though. It keeps dust off the element better, though you could use a clear disk over the reflector to do the same I suppose. For the size, I like the 20mm reflector the best. While the 27mm is ok, it's larger than the blade and makes instalation a pain. The 17mm works OK, but overall, I like the optics.

I still have some of the reflectors if you're wanting to try one. Just email me.


10-23-2007, 12:30 PM
No thats ok I just basically wanted to be reassured that they are pretty much the same. Like I said I already have one from the luke ultrasabers conversion kit. Thanks for the pic. :D

Angelus Lupus
10-23-2007, 12:36 PM
Just a random thought: Would there be any point/benefit in combining a reflector with a lens?

10-23-2007, 01:55 PM
Corbin (essentially) did something like this for me when designing and building the sabers for BOP I in 2006.

What he did was obviously use the optics in the emitter/mount... but inside the BLADE (in the ~2" portion that would not be seen by your eyes when the blade is actually in the mount/emitter)... he placed some reflective tape.

Now, for all I know--it doesn't make a big difference... but when I was playing around testing... it seemed to make a minor difference TO ME. Maybe it was the "if the mind believes it" thing, but... hey...

...it certainly can't HURT! :)

As to using an actual reflector cone/part WITH the lenses/optics... that would take some extra room, and you would certainly need to modify many parts, including the emitter--or make your own.

Doing it the way Corbin did this for a few of our blades--well, it seems to be an easy and useful idea.

10-23-2007, 03:16 PM
Yeah, as Novastar said, I sometimes would add some reflective material in the base of the blade with the reflective surface facing inward. It was supposed to help with the "sidespill" and to keep the base flare from getting to out of control. It helps a little bit I feel, but not a whole lot. If you have two blades right next to each other, then you might see the difference, but otherwise, it's subjective.
As far as using the stock reflectors with the stock optics, I'm not sure how well that would do. Both are made to sit right on top of the Luxeon emitter, and both obviously can't be in the same position at the same time.

Angelus Lupus
10-23-2007, 03:37 PM
Fair enough, 'twas just a thought anyway. I had thought of something like the reflective tape but wasn't sure how much differnce it would make.

10-23-2007, 11:33 PM
To add to the 2" of reflector tape kinda thinking... I like it--it adds brightness (IMHO), and can also be used to better stabilize diffuser film types (such as Corbin style, Ultra/Gelu style, Erv mixture, etc.) in place.

If I had it my way, all of my blades would be done this way. As it is... Gundamaniac and I are trying to get just that kind of thing done to ALL of the blades I have... which is like 20+ right now.

10-23-2007, 11:38 PM
I agree Nova.
I do that to all my blades too. I'm actually trying to find something super reflective that fits in the base of the blade and will act to hold the film in place as well as focus the light better. I've been looking for quite some time. No luck yet, short of having it custom machined, which I'm about ready to do if nothing else shows up.


10-24-2007, 11:04 AM
I think the tape is the best solution for the price.

Or, you could find a cylindrical (yet somewhat thin) piece of steel/metal/aluminum at a hardware store, shine the inside of it like nuts with some kind of buffing/fine grade sanding setup... and there you have it.

But--it seems like cost must always figure in to things... for example, what good would $15 tips be? Certain items are worth extra money... others--are not.

Angelus Lupus
10-24-2007, 11:13 AM
Well since I already have some sticky aluminium tape and the cellophane I put in my blade (single wrap corbin) is a bit lose, I think I'll try this.

10-24-2007, 11:29 AM
Right on! And... the reflective tape can act as a good material to put onto "empty" saber tips, too.

Sometimes--it's all about spending LESS on the unimportant parts... and MORE on the big ones...

11-08-2007, 06:31 PM
Corbin, thanks for the post, great information. i was actually going to order a 10 degree optic for my saber but will now go to a 5 which i thought would be insufficient. i generally use a long blade as i am tall, about 38-40 inches for single sabers, and 32-35 for saber staffs. i have not yet built my own saber, so i would have had to learn the hard way if it wasnt for your post, so thank you for the good info and great comparison pictures..

11-08-2007, 08:14 PM
Always a pleasure to meet a Jedi. :wink:

11-08-2007, 08:18 PM
call me a jedi when i do finally build my own saber, and it dont fall apart on the first swing...lol. oh and that damm "Padwan" thing below my name has to go too, so as soon as i figure out how to do that, it will bother me a lil.lol

11-08-2007, 08:50 PM
oh and that damm "Padwan" thing below my name has to go too, so as soon as i figure out how to do that, it will bother me a lil.lol

That's your rank, till you get to 100 posts, I think.

Only then, will it change to Jedi Knight.

Lord Maul
11-08-2007, 08:53 PM
No, it is his rank until 50 posts at which point he will become a Apprentice.

11-08-2007, 10:55 PM
wowZa.... guess ill have to find more things to talk about then... cool :)

01-03-2011, 09:07 AM
so if i use a 1" 36 inches blade is better use the 10" lens?

is that right?


Azmaria Dei
01-03-2011, 09:52 AM
so if i use a 1" 36 inches blade is better use the 10" lens?

is that right?


personally i like the 5 degree lenses for single die LEDs, and the 10 degree lenses for multi-die LEDs for just about any blade, but if you prefer the 10 in the comparison charts, then go with 10. the 5 looks to be spread a bit more evenly to me though.

01-04-2011, 09:31 AM
She has a good point, the five degree lense makes the blade more even, but I like the ten degree because it gives just a little bit a a flare effect at the base of the blade.

12-01-2012, 10:36 PM
So 5 degree lens for a 34 inch blade would be good then? I plan on using a trans white thin walled blade for Lee Filter show offs.

Jay-gon Jinn
12-02-2012, 01:32 AM
Since the store no longer carries the 10 degree lens, you now have a choice between the 5 degree and and the Rebel 8.7 degree. Both will work fine in a blade that size. I personally use the 5 degrees in my 34" blades, but I have also used the 8.7 before and not really noticed a difference.

I'm not convinced that a trans-white blade is the best bet for showing off a filtered white led. The white opacity of the blade is going to wash out or change the color of the filter, so you will not be getting an exact result. I'd use a clear blade with either of the lenses for that.

12-02-2012, 02:23 AM
The rebel 8.7 degree lens has a higher light transmission efficency than the 5 degree. As well, it works with ALL the single die LEDs in the store. I only use them these days.

12-02-2012, 10:47 AM
I'm not convinced that a trans-white blade is the best bet for showing off a filtered white led. The white opacity of the blade is going to wash out or change the color of the filter, so you will not be getting an exact result. I'd use a clear blade with either of the lenses for that.

I agree with Jay-gon Jinn; I've heard from multiple sources (trustworthy TCSS members and other knowledgeable forum members on other forums) that Trans White produces a pale, washed-out color. I've no doubt that it will work as a blade, but the color quality matters a lot to many people. If you're worried about getting the gift-wrap blade right, don't worry; it's not difficult. There are many posts around here that will tell you how. I am also available through PMs if you have any trouble.