(TV UV HV) Violet showdown - LEDGroupBuy vs SemiLED

[Milad LEDGroupBuy.com]

As the LEDs are using 120 degree optics in both situations, can you do a test which uses the full 19mm area at a distance of 11 mm away from the sensor to rule out different optical qualities. As there is no datasheet for either the SemiLED or the unknown brand you use, it would be hard to tell whether there is a difference in optical quality without using the full 120 degree spread. Thanks!

Its difficult to do the test at 11mm but I can see what I can do

 

All of them have the same optic, same board, same connector. We use the chip and then build it up with our components. Im just working on a jig right now to make sure they are exactly the same location for each test so we should get results that are comparative.

[Amdphenomx4]

Its difficult to do the test at 11mm but I can see what I can do

 

All of them have the same optic, same board, same connector. We use the chip and then build it up with our components. Im just working on a jig right now to make sure they are exactly the same location for each test so we should get results that are comparative.

Thanks! I just want to make sure there's no hot spot cause by the design of the emitter or the way the optics are fitted. If I understand what you're saying, you're using the same optics on both the LEDGB LED and the "Other" vendor's LED? Feel free to clarify.

[Milad LEDGroupBuy.com]

Thanks! I just want to make sure there's no hot spot cause by the design of the emitter or the way the optics are fitted. If I understand what you're saying, you're using the same optics on both the LEDGB LED and the "Other" vendor's LED? Feel free to clarify.

Correct. So basically we have the chip, board, optic and connectors. We put them all together and the only difference is going to be the chip.

 

The chip we are putting ours up against is the SemiLED chip on a XTE footprint.

[Amdphenomx4]

Correct. So basically we have the chip, board, optic and connectors. We put them all together and the only difference is going to be the chip.

 

The chip we are putting ours up against is the SemiLED chip on a XTE footprint.

Okay, thanks. I hope to hear the results soon. What were the results with the optics originally on the SemiLED LEDs as as a control?

[yury88]

Coherent PowerMax PM10 is the sensor

What specific kind of model the sensor?

 

Trying to understand the documentation and realized that there are several versions of the sensors

And is there a graph of the photosensitivity of the wavelength?

 

I understand that it is not linear and that is why 430nm showed the same result as 405nm

[Milad LEDGroupBuy.com]

What specific kind of model the sensor?

 

Trying to understand the documentation and realized that there are several versions of the sensors

And is there a graph of the photosensitivity of the wavelength?

 

I understand that it is not linear and that is why 430nm showed the same result as 405nm

its the standard PM10 part #1097901

 

What do you mean by the photosensitivity of the wavelength? The FieldMaxII-TO lets me set the wavelength to measure so I've switched it every time i took a measurement to match the LED peak.

 

Sorry I havent posted the video, im still waiting to get some time to complete the jig so its as close as possible to the same test between LEDs. Hopefully this week.

[yury88]

I just want to understand the principle of this sensor.

I understand it gives the absolute values ​​do not depend on the wavelength.

Ie to set the setting to 400 nm, and if the radiation will be 50mW, 50mW it will show?

Similar experience I could spend using a photodiode with a known schedule photosensitivity.

But this is the main problem, the reading will be true only when comparing LEDs with the same spectrum ...

[Milad LEDGroupBuy.com]

 

I just want to understand the principle of this sensor.

I understand it gives the absolute values ​​do not depend on the wavelength.

Ie to set the setting to 400 nm, and if the radiation will be 50mW, 50mW it will show?

Similar experience I could spend using a photodiode with a known schedule photosensitivity.

But this is the main problem, the reading will be true only when comparing LEDs with the same spectrum ...

My understanding of it is depending on the wavelength you set it at, it gives you the most precise measurement of power on that wavelength

 

If i set it to 400nm and measure an LED that is 410 or 420 or 430 or 660, it will give me a measurement but it won't be as accurate as if I set it to the different wavelength as I changed the LEDs.

 

So changing the wavelength from each test is going to give me the most accurate reading.

[yury88]

If it really works so, it can even be used as a spectrometer?

[Milad LEDGroupBuy.com]

If it really works so, it can even be used as a spectrometer?

Well it doesnt output like a spectrometer, its designed to measure power.

Would you guys rather see the results under a spectrometer instead of the power meter?

[yury88]

I understand that this is a power meter.

Just hypothetically possible to make a lot of measurements for different wavelengths and plot the spectrum.

But it is provided that the photosensitivity is independent of wavelength (as photodiodes).

[Milad LEDGroupBuy.com]

Here is more detailed explanation from one of our engineers on the sensor:




To answer one of the questions on the thread there: The sensor is a thermopile and measures total energy flux. It basically sees all wavelengths of light mashed together as a blob of "heat" or energy rather than seeing the specific wavelength like semiconductor based photodiodes do. The sensor material isn't as sensitive to wavelength variations as, say, a photodiode is but there is still a bit of variance with wavelength due to the optical properties of the thermopile sensor element (there is no such thing as a perfect absorber). So they create calibration curves for the sensor to take this into account. Since LEDs emit light in a fairly tight spectrum, you can set the meter to the peaking wavelength to correct for the slight variations in the sensor performance with wavelength. If you are using white light or an unknown source of light it doesn't matter a whole lot. The calibration makes more of a difference when you are using narrow bands of light like in lasers and, to some degree, LEDs.

[yury88]

Oh, this is a much more advanced technology than the one that is based on photodiodes.

I can not wait to see the video.

P.S You should be happy to have such toys =)

[bendel]

If I look at the specs:

(from www.ledgroupbuy.com/)

405nm 640-680mW radiant power @ 700mA

430nm 880mW - 960mW @ 700mA

(Semiled C35L-U-A, bin 360mW @350mA, the US version S35L should be similar)

420nm 610mW @ 700mA

 

So the 430 and 420nm measurements seems consistent relative to the specs. 430nm is nearer to the most efficient 450nm royal blue, so a higher efficiency seems natural. Just that 405nm comes out as the same is unexpected. These chips are not as efficient as the LEDs with higher nm. So maybe the power meter does a wrong adjustment. Maybe just measure all with the same setting to check the influence?

[1.0reef]

How do yours line up against Stevesleds 420nm?

[Amdphenomx4]

So have you done any more tests with the LEDs closer to the meter and possibly with the original optics included with the LEDs?

[rO.oster]

bump, any updates to the testing in respect to the control conditions?

[Milad LEDGroupBuy.com]

How do yours line up against Stevesleds 420nm?

We don't have them to test but someone was saying they are SemiLED chips

 

So have you done any more tests with the LEDs closer to the meter and possibly with the original optics included with the LEDs?

Yes/No. We have a jig that we did some tests with that keeps the LEDs in the same spot each time. There is no such thing as "original" optics. we have to put optics on the chips but we use the same on all 3 so the tests are basically showing you the difference in the chips rather than the components.

 

bump, any updates to the testing in respect to the control conditions?

Yup, publishing the video right now, should have a link soon

[Singlefin]

I'm a little lost. How does the hyper violet compare to the true violet? They weren't available when I made my original order from you. I just ordered a couple to add to my setup. Thanks.

[jedimasterben]

Different wavelength, hitting the 430nm peak of chlorophyll a.

[Singlefin]

Thanks. So translated to English, better full spectrum for colors and growth?

[jedimasterben]

Mostly growth. It will still excite a majority of fluorescent proteins, but chlorophyll a is the primary producer of energy in corals and clams, so it's best to hit it as hard as possible.

[Singlefin]

Double thanks. Should've paid attention in science class.

[Milad LEDGroupBuy.com]

Here is the video:

[yury88]

Thank you very much for the video.

Very clear and easy to understand.

Competitors can now only charge you is that there is no documentation on the diodes...
By the way, you do not plan to release the datasheet for diodes or at least chips?