Explanation LED modules
What does it mean lumen and lux ??
Lumen tables up to ten
HINTS TO THE EXAMPLE:
The adopted bulbs in our example is an LED and has about 5000 lumens.
The LED used in our example is a " surface emitters ".
Commercial LEDs have a free radiation 65 -110 degrees .
With 65 degrees comes to the object (in this case the fish ) approx. 5000 lux .
Notice : If would be the lamps a "point source" (for example bulb ) then would measured on the object only aprox. 398 lux.
CONCLUSION :
Lumen = Lux
- when light is not directed in a specific direction (for example, forward), or is directed
- and if nothing prevents the spread
RESULTS:
Has a specified lamp 5000 lumens and the light is not focused (e.g. by a reflector or lens) and nothing stop the spread (e.g. glass), thus it can be measured 5000 lux on this lamp at one meter distance. However, 5000 lux is not enough for a dive light, especially when the source has 5000 lumens.
What prevents the spread and to what extent has this impact?
Lamp (same example as before with 5000 lumens) illuminated through a 10 mm thick glass window.
At the object (in this case the fish) arrives only about 4000 lux at one meter distance.
CONCLUSION:
Lumen not equal Lux !
This results in a loss of about 15 - 20% through the thick pane of glass.
Is the glass in addition dim or tinted, loss is many times greater.
All 3 bulbs have 2000 lumen according to the manufacturer!
But they do not get the same light intensity (lux) to the object
Therefore, the black light bulb is bright (with its 2000 lumens), but unfortunately, almost no light comes on the object fish (only 200 lux)!!
MORE EXAMPLES :
Not only has the glass „destroyed" the lumen expansion, but also any medium which is located between the light source and the object prevent the spread. Rough Guideline: Every medium, which stands in the way of the spread takes approximately 10-15% loss with it.ATTENTION : Every dive light has at least 3-5 media transitions !
Therefore : The specified lumen to the manufacturer based on the built-in LED says absolutely nothing about how many lumens are actually available!
At the object (in this case the fish) arrives at one meter distance about 60 000 lux
CONCLUSION:
Lumen directed in one direction = much more lux!
By steering / in a certain direction / angle much more Lux will be created on the object!
SUMMARY:
- Lumen tells us nothing about how bright my object is what I illuminate.
- More lumens do not mean that the object is brighter.
- Only in connection with the Lux specification and angle I can see how much light comes on what area of my object.
HINT: Torches should have about 20,000 to 30,000 Lux, at about 10-15 ° radiation.
ADVICE: Good diving lamp manufacturers provide about 20,000 to 30,000 lux with 500 lumens!
However, anyone who thinks that 3000 lumens and more are needed to build a good diving lamp and these values can only be achieved through many lumens; the one is on the wrong track.
There are even manufacturers who install 20,000 lumens! BUT: We have already learned that 20 000 lumens are not equal 20 000 Lux !!!!!! But this is only the case, if I do not install anything (like a glass plate) in front of the LED, which is definitely not possible with torches!
To get right to the point:
Everyone is talking about lumen, but it"s not always about more lumen, but solely about how lumen can be converted into useful and usable angle lux!
The secret of a good dive light is the conversion of lumen in lux and the angle of radiation. Not much