Your new ST1300 comes with a pair of wimpy 45W/45W bulbs. Speculation as to why Honda installed these goes back to the US Regs and the maximum wattage allowed in a single reflector unit. The dual headlight bulbs in the ST1300 are not totally separated in a sealed independent reflector housings and thus in actuality, the 2 reflectors share an open space between them. So they may be interpreted, by regulation as one headlight unit and therefore the total output limited by law. Anyway,  I don't like them and there are better solutions out there.

    I caution you, no, I warn you against getting carried away here and installing a pair of 100w/80w in the bucket, you reallllllly don't want to do that. To much heat!!!!! melt city. Stay with the 70w/65w bulbs as your maximum wattage.

    I like as much light as I can get and I will not put a colored bulb in the headlight. Color is a coating and a coating stops a degree of light from passing through the bulb glass. So the easiest way to efficiently, and cost effectively put more light on the road is to buy  $19 bulbs like me, or cheaper where ever you find them,  or add in a separate wiring harness to include a relay, an in-line fuse and a nice set of running or fog lights with the additional mounting hardware.

    In order to be able to use H4 bulbs in the ST, you will need to use one shim per light bulb. That is the grey circular device shown below. They are around $12 for a pair of them.  These shims are laser cut stainless steel so you will never need another pair!  Honda uses a proprietary bulb in the ST1100 (all years).  You must trim off the bottom 2 tabs so that the bulb will go into the housing.  Here is where the problem lies; doing so actually causes the bulb to point up, not straight as needed for proper light disbursement - these shims correct this problem.  Upgrading your bulbs without the use of the shims can actually REDUCE your light output because the bulb will sit too far into the housing. 

Shim

Here is a nicely written procedure on how to do this with pictures, good job Curt.

To adjust the beam to shine where you want it, click on this next picture.

Note: With my long fingers and large hands, I found the best way to get my hand in the area behind the fairing and change the drivers right side headlight bulb was to stand on the drivers right side of the bike facing towards the rear of the bike, turn the handlebars to the far left and reach in with my right hand with the palm facing the drivers right side rubber dust boot. Of course you would reverse you position for the drivers left side of the bike. This was the only position in which I could squeeze the two sides of the H4 plug to get the plug to release the bulb.

    I have tried so many bulbs, blue ones, yellow ones, Silverstars, Osrams, PIAA, and my favorite of the DOT compliant H4 series, Osram Silverstar Plus 50. They are 60/55W bulbs and it rates closely with the GE Megalicht +50 or Phillips Vision Plus bulb.  You can not go wrong any of these  bulbs.   The H4 +50 bulbs from the big four reputable European bulb makers (Philips VisionPlus, Osram SilverStar (not the H4ST), Narva RangePower+50, Tungsram Megalicht) are functionally identical. When 10 samples of each are put through photometric, optical comparator and life tests, there's a very narrow range of performance and life differences, and those differences are randomized among the four brands. If you are wondering is it really 50% brighter, I will tell you sort of. These lamps provide up to 50% more light on the road ahead at a distance of 50 to 100 m and longer illumination up to 20 m.  The way manufacturers compute the +50 value isn't how the average person would think it would be done. Its not an all out 50% more light in the whole beam pattern. Nope it is more concentrated than that. If fact it refers to the area of the beam where the light is the brightest and how much further down the road it goes. That area is to the right of the center of the beam.  It's the area of the road ahead at a distance of 50 to 100 m and longer illumination up to 20 m. that gets the extra light not the area to the left or right of you or even directly in front of you, it's the area ahead of you. So if your testing bulbs in your garage on the garage door trying to figure out which bulb is brighter, your not going to really be able to discern the enhanced beam pattern well at all. 

    Here is a link to an document which shows a comparison between a standard H4 and a H4+50 bulb. http://www.candlepowerinc.com/pdfs/SBL_Headlamp.pdf  +60 bulbs are the best output you are going to get in a "DOT stamped bulb" solution.