I know that this topic has been discussed before but I'm pretty amazed by the differences. I just switched my Osram D2S to Philips 85122 D2S, and Philips is better in many ways. I'll try to take some pictures with my digital camera but I don't think my camera is that great. However, visually, right off the start, Philips bulb starts off bluer and finishes off bluer too after the warm up. This is especially obvious when you stand a with your knees against the bumper and stare down at the headlight lenses with one being Philips and another being Osram. And I'm almost positve that the philips are visually 5 to 10% brighter than Osram. Once again, the differences I am talking about are so visually obvious that just about anyone can tell.
This has been beaten to death here and on other lighting forums, but the reason the Philips light output APPEARS brighter when looking at it is because of the additional blue-frequency light being produced by the Philips capsule. The human eye is easily tricked in judging relative brightness, especially when looking at blue-shifted light. The only way to be certain if one light source actually has more luminosity than another is with a calibrated light meter. The lumen rating for the Philips and Osram bulbs is the same AFAIK, so the down-the-road lighting should also be the same, unless the arc locations of the two capsules are different. Case in point: I have a set of the Sylvania X1010 auxiliary headlights (very blue) and a set of the Hella XL auxiliary headlights. When looking at them side-by-side, the X1010 APPEARS to be producing MUCH more light than the XL, but for down-the-road lighting improvement, the XL lights win, big time. And the XL lights do this with the lowly H3 55W halogen bulbs.
