The question is about who uses high beams during the DAY.
Since I have converted to led's I usually just use the low beam during the day.
The times I have used the high beams is when I am with of the pack of riders who all run lights on high beam so that the leader can keep track of us... usualy four to six bikes in our group... The other time is when I am splitting lanes in heavy traffic. No modulator.
Now go get a beer and some popcorn....
Those of you who are using halogen lights need to know that the high beam has a lower life expectancy. Standard bulbs are 1,100 hours on low beam and only 230 hours on high beam. If you are using silverstar bulbs the low beam is only 150 hours and the high beam is worse at 50 hours. Carry spare halogen lightbulbs! Leds will give you more than 5000 hours or 300k miles.
Our vision has a staggering dynamic range from starlight to daylight in a snow field. It is more than 100 million to one. The darkside of our vision is handled by our rods, which we do not want to use for riding. The bright side of our vision uses our cones which gives us color and sharp center focus. The magic threshold where our vision switches gear is about 0.1 candle power or 1 lumen or 1 lux. This is an important metric to know. If you look at the beam patterns published by the top light makers the max range is defined at 1 lux. That would be between 200 to 300 feet for the halogen low beam (depending on the design of the reflector and lens) and up to 600 feet for the leds.. Now you can see much further than 600 feet but you are now using your rods and objects will look grey and you will start to loose your center sharp vision.... there is a broad transition here.
Ok the point here is that your super powerful lights are giving you 1 lux of light 600 feet in front of you at night which is a lot to see with. Now the noon day sun is going to give you 100,000 lux at 600 feet and everywhere else! There is so much light during the day that your High beams pale comprared to the power of the sun. Now your pupils which were wide open at night will constrict in the day reducing the light by 1/16. Your eyes will auto adjust for the rest of the range. Even on a gray cloudy day high beams are really not that bright...
So you are "safe" to use your high beams to be conspicous. But you may annoy some other drivers, that is a different matter.....
Here is a photo where the three bikes are all using high beams, the two ST1300 bikes in back are using Evitek G6 bulbs, The motorhome is using low beam.....