I could have selected my wording more carefully perhaps, but by "orientation" I was meaning "direction".Major Softie wrote:...there are two differences you did not mention....The incandescent is not "shaded" in the direction of the oncoming traffic the way the H4 is...[and)...the filaments do not travel in the same direction...
Regarding the shading, my Bosch lens/reflector assembly has a metal dish-shaped cutoff shield mounted forward of the bulb so that no light form the bulb, incandescent or halogen, ever directly reaches the lens, so that shouldn't be a factor either.
The only other consideration I can think of is that the colour temperatures of the two bulbs would refract differently, but this difference would be so small that it would not even be perceptible at all.
I'm continuing to be unclear on why the Bosch lens would cause light from an H4 to be "spread about and awful" in any appreciable way.
I have a reasonably well-trained professional eye when it comes to light-casting and I've yet to detect anything I'd consider problematic with the H4 from Bob's.