Optics definitely count; roughly the same lumens, very different results

I reported two of my mods here in separate threads some time ago, namely maghid and 2D mag + 4*seoul. I took the beamshots for both mods exactly the same time, same place, even the same camera stand position, under exactly the same environmental brightness conditions... So I created accidentally comparison "contest" between maghid and magseoul even though it took me one *month* to recognise that... (How to make mr. Nereus yell "THAT'S FOUR!" in august? - by asking him "What is 2+2?" in january!!! )

Way too much fun laughing at myself - have to get back to topic (I don't want to hijack my own post before I have even written it! - although there is no specific CPF rule against that, I guess ) So I am not providing you with any new pics, just combining the pics in two separate threads and pointing out some differences. Sooooo, lets get started with the maghid vs. magseoul comparison!

Here is magseoul - some 800 bulb lumens:



Here is the maghid - some 600 bulb lumens (slightly overdriven ballast):



So what do we have at hand? 800 blumens of led power and 600 blumens of hid power... pretty much the same, especially if you take into account the fact that human eye is not very sensitive to so small relative differences in lumens (25% in this case).

It is the OPTICS... that's where we have major differences.

First some indoor beamshots; below is maghid (and poor std 2D incan mag as a benchmark):



Below is magseoul (and again the std 2D mag):



White wall beamshots tell you that the maghid is more focused... even though the magseoul is brighter and has more sidespill.

Next close distance beamshot, maghid and the benchmark, std 2D mag, side by side:



Below is the magseoul (and the benchmark):



The difference between the maghid and magseoul is much clearer in the pics above...

Far distance (ok, ok, CPF member Ra might say that this is CLOSE distance beamshot but that's another story ) beamshot with maghid; distance to the shed is 200m:



The same camera stand position, same place, same time... you can see the shed there with magseoul too, although not so well:



maghid, distance to the shed is 300 m:



You can barely see the shed with magseoul too, but unfortunately I could not take a proper photo of that. So this is where the upper limit of magseoul throw kicks in.

So what is my point here? Maghid clearly out-throws magseoul even though the latter has more lumens as can be seen in the white wall beamshots above. I think the difference between the two mods can be best seen in the close distance beamshots, the magseoul really beats maghid by illuminating way larger area. The lumens is pretty much the same; we have two different approaches here:

You want throw? Use small point-like light source and use one big reflector. That's the "power is nothing without control" approach.

You want flood? Use many light sources (hipo leds) and many small reflectors. That's the "there is no substitute for cubic inches" approach.

Thanks for looking!

-N

:goodjob: Nereus

Nice beamshots and also nice lights:rock:


Best regards

______
Tom

I think you mean "There is no replacement for displacement."

There are, these days - but a story for another day...

Very cool beamshots! Looks cold outside, too!

Hi Nereus, Thanks for the PM..

Great work !! Especially the mod's !

Optics indeed are very important: They determine the overall eficiency of a flashlight!

However.. If the discussion takes a turn in the direction of lumens versus throw, there are other factors involved !!
Converting lumens into a nice flood is not as hard as converting lumens in throw.

The key word is surface-brightness.
If you want throw, ofcource you need lumens, but you need high surface-brightness as well!! The lumens need to come from a surface as small as possible!

And here comes the inevertable: The difference in throw, your pictures show, is not quite a matter of different reflectors, its the difference in surface-brightness of the source.
As the revolution in the LED-world goes on, particular if it comes to efficiency and surface-brightness, they still have a long way to go to reach the surface-brightness of HID !!

Led's already are about to surpass the best halogens on surface-brightness

But today, if you want to reach the same throw with leds as with HID, you need a reflector with a larger diameter.

Especially with the Solarc 10 watt HID, extreme throw is possible: With a very high quality, super mirror-smooth reflector, you can concentrate on one of the hotspots of within arc. With a 48mm reflector, my mini-HID reaches 250,000 CP, that means 1 lux at 500 meter distance!

With the best led's of today, you still need a 150 mm reflector to reach 250,000 CP's !

The throw of your HID-setup is much closer to the throw of your led-torch because of the slight orange peeled reflector you use in you HID: With that setup you will reach about 70,000-80,000 CP's..

Do you have a lux-meter?? Take measurements of both torches at 20 meter distance, and tell me (or us..) the difference !


Best regards,

Ra.

Very well said! The results came out just as i expected. But thanks for the pics!!

Now that I visited countryside I had a chance to take a few more beamshots.

Here you can see white wall beamshot with std mag 2D as a benchmark. Magseoul is on the left and the Maghid on the right. The former has clearly brighter sidespill and the latter brighter hotspot:



Close distance (3m) beamshot, magseoul on the right:



Close distance (10m) beamshot, magseoul on the right:



It is easy to see that maghid has tighter focus. I have bought a lux meter and I am planning to carry out some measurements but I am a bit busy now...

-N

How did I miss this thread?? Great pics of some even greater lights! :goodjob: I really like the beam of your Mag-HID....very smooth!

Thanks!

Measured following center beam brightnesses: magseoul 700 lux @ 4m, maghid 5000 lux @ 4m. Calculating more familiar units: magseoul 11200 lux @ 1m, maghid 90000 lux @ 1m. You can not see this difference in the beamshots because pics are saturated.

No need to wonder why maghid throws better... :green:

-N

So now we need Nereus' Monster MagHidSeoul, also known as the A2 overkill: a ring of P4s around a 10W HID, so you can choose between flood and throw. With the right UI, you even get runtime

The way to obtain throw with leds is by using an Aspheric lens.

Lux has been measured at 75000 at 1 metre when powering a P4 Cree-XRE
at 1000ma using a 50mm Aspheric lens in a mag-mod.

With Q5/R2 XREs, this would be very comparable to the 90000 lux at 1 metre
you mentioned for the magHID.

IMO, if one were able to design an led light with an Aspheric lens in the middle,
surrounded by leds in reflectors, this would possibly achieve an ideal light
with both flood and hid-type throw.

I didn't use relfectors for the flood LEDs, but I did the combination of asheric + near range LEDs.
I think this concept is more flexible and performs better than a setup with changeble focus.


What is not shown clearly in this picture is that the asheric has the full idameter of the tube (55mm). Must be because I was too close to the lamp when doing the picture. I'm not that firm in optics, but Ra often entioned the fact, that the larger a lens/reflector is the farther you have to get away from the light to take pictured or do LUX readings.