whats the lumens of the stock 9007 philips jetta bulb?

Re: whats the lumens of the stock 9007 philips jetta bulb? (Lumalux)

It’s a huge subject but I will try and keep it as simple as I can so it’s not just a discussion between 2 industry insiders.
Firstly colour temperature is purely the X Y co-ordinate on the black body curve. It has nothing to do with brightness or lightoutput it is simply a colour point. On all image manipulation software like Photo shop, Corel draw you have colours and that colour has a co-ordinate usually an RGB mix (Red Green Blue). This is EXACTLY how the colour co-ordinate is based for Colorimetry for lamps. It is still a mix (as all light) of RGB but is expressed on the colorimetry graph as an X and Y co-ordinate and as such has a colour temperature rated at xxxxx degrees Kelvin.
Lumen spec on a light source and here on car lamps is measured in a photometric sphere and is the measurement of the TOTAL light output from that lamp. This is where the R37 and DOT specs are drawn up.
However the important performance aspect on a headlight beam is its distribution and luminance. Luminance is a figure taken at the filament and is expressed as CD/M2. It is in simplistic terms how bright is that single spot on the filament as opposed to how much light is the whole filament giving out. Why is this important? Well your reflector and lens collect 10000's of images of the filament and distribute them up the road. You beam is infact made up of 10000 of images of your filament. The art of the headlamp designer (now done on a computer) is how to distribute these images. If you want to try and prove this park up in a dark garage and turn all the lights off except your headlight. Cover the side you don’t need and park up a few feet from the wall. Now take a piece of card big enough to cover your headlight and make a nail size hole in it. You will now see with some movement a single image of a filament on your garage wall. Move the card around over the headlamp lens and the filament will move. What infact is happening is that at each point on the lens you have a different image of the filament.
Now if you take that filament and reduce its size and burn it harder it becomes 'brighter' expressed as a higher CD/M2. If each of the filament images on the road in your beam are now brighter you have better headlamp performance
mmmmmm a tad long but I hope this helps
Oh and before anyone asks you will never be given the CD/M2 figure from any lamp as this is 'Industry Secrets' so no need to ask!!!!!!!
Nick