Flashlightlens.com UCL test results

I recently sent a few lenses out to Roy in order to test the light transmission compared to stock poly. Here's what he measured:

The test were performed using an un-compensated photocell and a multimeter. The numbers are the mA measured of the output of the photocell.

For the 52mm UCL lens, a DD Maglight with a LED for the light source was used.

The average of 10 samples with and without the lens were measured. 468.6mA with no lens and 465.7mA with the coated lens. Transmission was 0.9936 or 99.36%.

The average of 10 samples with and without the OEM plastic lens were measured. 468.1mA with no lens and 428.1mA with the OEM lens. Transmission was 0.9145 or 91.45%.

The Borofloat glass lens for the AA Minimag was tested in a similar manner but using only 5 samples. The light source was a AA Minimag with the Opalec led conversion.

526.2mA with the glass lens and 562.4mA without the lens giving a transmission of 0.9356 or 93.56%.

514.2mA with the OEM lens and 555.8mA without the lens giving a transmission of 0.9252 or 92.52%.

These results reinforce the claim of about an 8% increase in brightness when using the UCL lens and 1% with the Borofloat.

Never mind

A point I faled to mention was that the 52mm lens was a UCL lens with AR&AG coatings.

The lens for the minimag was not supposed to be tested,but as I was set up for making measurments, I went ahead and tested it anyway. I assume that it was a non-coated lens.

Yo moderator, please delete my posts here.

Thanks,
Don

Sorry, I forgot to mention the 22.6mm was for the Borofloat lens and not a UCL. The post was edited to make this a little clearer. Also, that 4 was supposed to be a 5.

Chris

[ QUOTE ]
flashlightlens.com said:
I recently sent a few lenses out to Roy in order to test the light transmission compared to stock poly. Here's what he measured:

The test were performed using an un-compensated photocell and a multimeter. The numbers are the mA measured of the output of the photocell.

For the 52mm UCL lens, a DD Maglight with a LED for the light source was used.

The average of 10 samples with and without the lens were measured. 468.6mA with no lens and 465.7mA with the coated lens. Transmission was 0.9936 or 99.36%.

The average of 10 samples with and without the OEM plastic lens were measured. 468.1mA with no lens and 428.1mA with the OEM lens. Transmission was 0.9145 or 91.45%.

The Borofloat glass lens for the AA Minimag was tested in a similar manner but using only 5 samples. The light source was a AA Minimag with the Opalec led conversion.

526.2mA with the glass lens and 562.4mA without the lens giving a transmission of 0.9356 or 93.56%.

514.2mA with the OEM lens and 555.8mA without the lens giving a transmission of 0.9252 or 92.52%.

These results reinforce the claim of about an 8% increase in brightness when using the UCL lens and 1% with the Borofloat.

[/ QUOTE ]

Have you ever measured borofloat with AR (anti-reflective coating) on it though?

How would a lens like this affect the %65 rule of thumb for bulb lumens and lumens out the front?

holy thread revival batman!

Might as well jump on the thread revival train....

I imagine the glass lenses give significant scratch resistance when compared to original plastic lens? Also, at what point do you have to worry about thermal shock?

Answer: When the light emitted burns paper in 4 seconds. LOL.

Bill

I found an interesting phenomenon when I was testing for total output of lights: the use of AR glass vs. non AR glass in a light did NOT affect the TOTAL output I measured, within an accuracy of 2-3% (analog meter). It affects the brightness of the center spot, but not the total.

My theory is that light reflected back by non-AR glass just hits the reflector again and (most of it) just goes out the window at a different angle, i.e. the non-AR glass moves the photons from the hot spot to the spill. Very little photons are absorbed in the glass window itself or are reflected back into the LED and lost. I think absorbing lens materials (diffusion screens, frosted tape, whatever) would reduce total output, but not lack of AR.

Someone else might try this measurement to see (basic rule of science) if they also get this result.

I have the UCL lens with LDF covering. It produces a very useful beam, but does anyone know how much light is lost?

I have now tested 30+ diffusers ( many films).
I have a ucl from flashlightlens.com with LDF.I tested mine at 10.6% loss.
On said light I lose 14 lumens and gain one hell of a fantastic wall of light.
IMO it is worth ever penny and I will never remove it.

I am using a 52mm UCL with LDF on my Chameleon Chamelhead (Mag D reflector) and am showing slightly less than 4% loss (bounce with lightmeter). I am very pleased and like the "wall of light" effect. Chameleon has been modded with a Seoul P4.

Bill

I found an interesting phenomenon when I was testing for total output of lights: the use of AR glass vs. non AR glass in a light did NOT affect the TOTAL output I measured, within an accuracy of 2-3% (analog meter). It affects the brightness of the center spot, but not the total.

My theory is that light reflected back by non-AR glass just hits the reflector again and (most of it) just goes out the window at a different angle, i.e. the non-AR glass moves the photons from the hot spot to the spill. Very little photons are absorbed in the glass window itself or are reflected back into the LED and lost. I think absorbing lens materials (diffusion screens, frosted tape, whatever) would reduce total output, but not lack of AR.

Someone else might try this measurement to see (basic rule of science) if they also get this result.

Click to expand...

This is fairly logical reasoning. Of course, light that is say reflected back into the lamp, or into the black bezel etc. will be absorbed/lost. It means that the most significant factor for overal output is going to be the quality of the reflector coating. This is why the ~35% loss of light in a lot of these incan lights doesn't make a lot of sense to me -- empirically it's been demonstrated, but I don't know why the number is so high. Assuming that all the light is reflected off a reflector (none going straight out the front) and that all the light reflected off a non-coated lens is completely lost (not bouncing then being re-reflected), that implies that the reflector surface is only about ~70% efficient. (Both of those assumptions are "worst case scenarios", real results should be better than that)

I notice the same overall effect though comparing reflector lightbulbs to standard lightbulbs of the same wattage and lifespan. A standard bulb will be rated at something like 800 lumens, while the reflector bulb will be more like 600 (25% loss). However, there is usually almost no difference between frosted bulbs and clear bulbs -- so the loss must be coming from the reflector surface, as opposed to the frosted glass. This seems to disagree though with the findings that frosting flashlight windows reduce light output by ~10%.

The stock LED in a 4D mag was not very good for a walking light. The UCL with LDF turned it into a great light! It now gives me sufficient throw and a nice wide beam for walking my dog.

I just received my UCLs last week and installed them on 4 Mag LEDs...well, two of them were Terralux's. What an inexpensive and useful upgrade they are. Just the fact that they don't scratch and discolor is great in itself. Add to that a little increase in output and it's the icing on the cake. Thanks Flashlight Lens. :twothumbs

I've been using UCL's with LDF on my lights and I am really liking them. I initially was not happy because I was looking for more up close flood but after using them for a couple of weeks (especially outside) I am very satisfied. The LDF still allows for some throw but provides enough flood to light up my backyard. I find the increase in flood to be very useful and preferrable. Customer service was very good at flashlighlens.com.

I have a 2C Mag with a Diamond 1w LED. It throws a tight spot that's way too tight. Turning the focus out for more flood produces the very predictable hole and rings Maglite pattern. Any ideas if a particular lens upgrade, with or without any coating, would help? I considered a replacement reflector, but it's not easy to make the right choice for throw/flood balance. Any suggestions to make my 2C Mag a better performer would be greatly appreciated.

Thanks

Bill, as Oddjob had mentioned, the UCL lens with LDF coating provides more spill light but still throws pretty decently too. You can order them here:
http://www.flashlightlens.com/item--UCL%AE-Lens--UCL_Lens.html

You'll want the 52.1mm x 1.90mm lens, plus the $3 dollar option for LDF coating.

You would probably be happy with a light or medium orange peel aluminum reflector if you don't feel like going with the LDF coating...but you still want a UCL lense in either case. The UCL provides a 9% increase in light transmission over the factory mag lens.

All that being said, the UCL with LDF is probably the easiest thing to try first. I'm very happy with mine.