Diffusion Techniques Testing - Various Methods

I've only been on my bike 3 times in 2014 and none of those times was in the dark with a light. (And 2 of those times were slow gentle family rides.) I would expect a light that gives wide flood while still having good throw to cover most needs. MTBers generally also wear a throwy headlamp for looking ahead / around corners. That's not something I've tried yet.

I think that wide angle lens can be cut down. You could also experiment with magnifying lens sheet.

I thought about throwing in the Glad Press-n-seal too. Maybe in the future.

Sorry, I don't want to ruin my wide angle lens by trying frosting on it.

The pen used is my favorite - Pilot G2 Gel. I think that one is the 0.7 thickness. I've never been told I had good handwriting.

-Garry

Thanks for sharing this work garrybunk. I’ve only had time for a quick look. (I skimmed all of the text and briefly scrutinized each photo & mouseover.)

Useful info for me. I also rarely ride, but to me the wide angle lens looks like the best forward beam pattern. It’s too bad that it sacrifices some spill, but the column of light it sends forward on the ground seems to be unlike any of the others!

So the wide angle lens is smooth on the front and ridged on the back? And the mounting area around the edges is a uniform thickness which is less than the overall thickness of the ridges?

Nice work, Garry.

Correct on all accounts.

BTW-Looks like my photos are going to disappear again! I'm going to hit my PhotoBucket bandwidth limit very soon. Sorry. I'm going to have to look into another image hosting service I guess. At least you have the link to my gallery in the O.P.

-Garry

Try Google. Haven’t run into limitations yet for the free service.

Thanks for sharing Garry . Good job .

"...
Original Glass 49 15 91%
DX Glass 51 16 94%
Lightly Frosted 45 14 83%
Heavily Frosted 33 10 61%
DC Fix (Entire) 40 13 74%
DC Fix (Top 1/3) 48 15 89%
Wide Angle Lens 49 15 91% ..."

I especially like the percentages style of comparison .

I wish to see more of this .

Thanks. You know, I believe someone has tested DC Fix as having very little light loss. Not sure why I'm seeing so much loss in my test. Perhaps the light is cast so much to the side that it's not picked up in my ceiling bounce reading? Thoughts anyone?

-Garry

Yeah , I've heard about the supposedly small losses from DC-Fix , but I can't use it on my bike lights , as it definitely takes virtually all throw away . I need some throw when I'm going fast so that I don't outdrive my light .

For this reason , I only use DC-Fix on lights I will use for close up work .

i was going to say this too ....I've never tried press and seal glad wrap but I have some cheap sandwich bags that have small marks built into them and it makes the beam spread out just a bit .So you could orient the angle vertical or probably more usefully horizontal to spread the beam out . . Now i need to go get some press and seal ...

Maybe the reason you're seeing so much light loss is the meter is too far from the light .I thought dc fix was a lot less loss .. you may need to build a sphere:P

I use Glad Press n’ seal and it does what i want it to do.

Hmm . . . sounds like I need to test another method :) .

-Garry

Ceiling bounce tests are known to favor throwy lights over floody lights, even when they put out the same amount of lumens. It’s a poor substitute for an integrating sphere.

Using a light box, I tested DC-Fix before/after on the exact same light (for a few lights) and got a loss of anywhere from 2% to 7. Usually about 2 to 5, unless I get the film dirty while cutting or applying it. A loss of 26 is almost certainly a measurement error, not an actual loss of that much light.

As for throw, it definitely kills the lux… but that’s kind of the point. I usually see the lux drop to about a third of its original value.

Thanks for chiming in ToyKeeper; thought you'd be a good one to speak out on it.

-Garry

I’d found the post by Selfbuilt on CPF, his test showed 3.2% loss with DC Fix Sand.

I saw Stripes (not the movie), I’m curious to try it either on its own or combined w/ Sand to
see what it does.

http://www.berlinwallpaper.com/dcfix/images/stripes.jpg

Is there a DC Fix that has ribs rather than random?

Ha… answer my own question:

I thought it was about 3% loss.

Interesting. I wonder if anyone has already tried it. Let us know how it does when/if you get it.

-Garry

NightSpy, are you thinking straight ribs (DC Fix Stripes) or some other pattern?

To me, it looks like DC Fix is the clear winner.

I don’t know… I give the DC-Fix and the diffusion lens similar ratings depending on what you are after.
For tail lights, definitely DC-Fix (or aspheric or modified aspheric), for distance and close-up, the diffusion lens is a serious contender.