You guys are camera freaks you might like to check this for me-

The KE70 has pitiful lights, even putting a 90/100watt in one side completely unimpressed the daughter.. :o

The lights run power to the bulb, then back up to the switch for dip/full beam. The dip has a relay but the full beam earths straight through the switch.

Once it was dark tonight I hung a sheet of white plastic inside the garage door, put the wife's Nikon D70 on a tripod and aimed it at the white centre of a headlight. With dip lights on it used an F-value of 5.6.

I pulled the connector off that headlight's bulb and ran wires straight from the battery and back. Then it used an F-value of 7.1.

So it reduced the shutter size to take the same photo because there was more light... How much more??

Well, the F-stop system works on a factor of sq root of 2 to double the amount of light, so opening a lens from F8 to F5.6 doubles the light getting in. The square root of 2 is about 1.41, so thats the size change to double the light, and we saw a change of 1.27 to get from 5.6 to 7.1.

That multiplier of 1.27 is 90% of the usual 1.41 that F-stops are based on, and I'm wondering if that means we increased the light by 90% of double what it was. If that is the case then its worth fitting the relay circuit above and trying to get maximum light, nearly double what we get stock.

Anyone know how these F-values actually work in real life?? If they are some odd logrithmic graph then it may not be that much...

no need to be that mathematical keith. I got lost half way though. what is the colour of the car? what setting is the camera on? AV, TV, P full auto?. what colour is the car? you will find if you have AF on and there is any white the camera will focus on the white more then the car. what you can do is select the focus point manually. F values help. I'm still in the learning process and there are a few more blokes on here that have DSLRs, SMNT, DRJEKL, STEPHEN haha

haha- Yeah I figure those are the guys who know plenty. Jasetu also...

The camera was off to one side of the driver's door and the viewfinder only saw the headlight beam on the white plastic sheet I hung in front of the car, so it didn't "see" the car at all.

It was on a set speed, so it could only alter the apeture to change the amount of light going into the "film"- whatever the picture sensor is in a digital...

Dijo probably still has an old-fashioned hand held light meter somewhere but she couldn't remember where.

It worried me that you couldn't see the difference between the stock 55/60watt bulb and a 90/100watt H4 halogen! That's when I wondered about the wiring and switches being the problem.

Replace the current wiring, if you're going to use halogens that big you'll want to have relays doing the work for you. It's the only way to get decent performance out of your headlights unfortunately...