Why do I ask? Well firstly let me say I'm referring to a standard 7" round H4 bulb headlamp whether what I have to say applies to other types I don't know, but this is my experience... Recommended setting is to measure the height from the ground to the centre of the headlamp and and make a horizontal line two inches below that measurement on a wall, then there are various suggestions as to how far the bike should be from said wall, 17 feet or 25 feet, but in my experience this distance is moot. I might also mention that having a passenger on the back or a full fuel tank does change the light position slightly but no so much that I found it makes a difference. I recently bought a Philips extreme vision 130+ H4 bulb that had a tiny bit of blue on the periphery so it give a yellow light that is not as yellow as standard but not white. After adjusting the light as per the recommended setting, I found to my surprise that while it was brighter it did not really illuminate the road very much further in front of the bike, if at all. The high beam though was noticeably brighter. Ok so I drove around like this for a few weeks moderately satisfied. Until just for the hell of it I adjusted the headlamp to be two inches over this line on the wall rather than two inches under. I thought that perhaps it might be a little uncomfortable for oncoming drivers so I made sure it was pointed straight ahead or a little to the left. After a short while I got around to actually testing it by having someone drive the bike towards me while I was on the street and in various positions across the road from the curb to the oncoming traffic, and it was then that I realised that having it four inches higher than recommended did not blind oncoming traffic, all it did was make the headlamps look like a bright pinpoint of light instead of not being visible at all, or barely so during the day. Further I note that it does not illuminate the road any further in that the bulk of the light seems to fall not very far in front of the bike, although it is a lot brighter. In the daytime when the headlamp was switched to high beam it was painful to look at and when switched back to low beam, it was definitely a nice bright light but not in any way glaringly bright. In fact it's a lot less glaring that at least half of the cars that ride towards me and being on a bike I'm obviously higher than most standard cars. The biggest change I have noticed at night is that warning signs light up like christmas trees which I've never really noticed before. Even in the daytime they light up. When I switch to high beam at night, it is clearly high beam, it is not overly high but does the job perfectly. What I'm getting at is that with this modern H4 bulb and the lamp adjusted 4" higher than standard specifications, the headlamp appears to work and do it's proper job as you'd expect it to. I hasten to repeat that I have check it in the day at various locations and there is certainly no problem at all with it's height. Further it seems that warning signs are meant to be lit up otherwise they'd not make them reflective. If I had not done this test myself I would have assumed that it would appear to be a high beam. But I'd have been wrong. I feel much safer and the light works much better. I've seen motorbikes in the daytime with their lights on and often I barely notice them which is why I've been thinking about a modulator. No one has flashed me and indeed I would not expect it because it is not at all like when people have their high beam on, if it was I would not leave it like it is. I was a bit concerned at first seeing the street signs lit up during the day, but after double checking it's not overly high in real life and so they must be being illuminated by peripheral light, which is what I guess they are meant to do. Defensive riding and being seen are the best things a rider can do for his/her safety and after a few weeks of this I feel a lot safer now. So I put this out there and I'd be please to hear anyone's thoughts about this.