But it's not rated in lumens as that is pointless rating.
You're welcome to your opinion but I don't agree with this statement.
AFAIK, light output from any source is usually measured in lumen and that is the only accurate method of comparison between different bulbs or light sources.
What the salespeople leave out, is that beam angle, colour temperature, and reflectivity of the destination are just as important parameters to consider.
Whereas lux is the resultant illumination of the surface or destination at a specific distance and is based on all the above.
If we were to use lux to qualify different bulbs, it would be necessary to perform a myriad of qualifications on the value, such as beam angle, colour temperature, and a specific distance to the destination, from the light source, etc.
It would be necessary to qualify that the resultant lux from 'the said bulb' will be X based on a specific reflector or projector housing because each housing will have a different result.
I do agree that marketing does not provide sufficient details and will always make an effort to distort and manipulate the facts to make their product appear better than another.
There's not going to be enough difference to notice between 9000 lumen and a 10,000 lumen, especially considering that rating is split between both bulbs on these LED lights 20k total. That's not per bulb, you have to read the fine print.
I do agree that subjectively, we're not too likely to see much difference between 9,000 & 10,000 lumen and that the higher output is a newer release of the product but...
As you mentioned, there are 2 bulbs. So, now the increase is 2000 lumen, and even though the resultant lux will not be much more, it is still more.
If the cost is almost identical and it is an updated version, why would I choose the older model with less light output?
Light output is measured in lux, I'm at is the only true measurement of output.
Light output is usually measured in lumens, and lux is the result at the surface or destination, at a specific distance.
The following article has a clear definition of the difference between lumen and lux.
Easy to understand graphic explaining the difference between lux and lumens as well as a conversion calculator.
www.waveformlighting.com
These are a couple of quotes from the above link.
The difference between lux and lumens by definition
The core difference can be summarized as follows:
- Lux is a measure of illuminance, the total amount of light that falls on a surface
- Lumens is a measure of luminous flux, the total amount of light emitted in all directions.
Lux is a measure of how much light falls on a particular surface and can be the result of multiple light bulbs and even daylight mixed in.
On the other hand, lumens is important for knowing how much light a single light source emits. This is useful for comparing the total amount of light a bulb emits, but depending on its light distribution and space size, whether it is "enough" for a space or task cannot necessarily be determined.
YMMV
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