Mirror lockup and WB help on XT

Ok, i'll start with the mirror lockup. A few people mentioned to me that i should use mirror lockup on some long nighttime exposures to reduce any camera shake that might happen. I didn't even realize how to do it till after i took my pics. I accidentally left the mirror lockup enabled and when i took a pic today, the mirror flipped up but stayed that way. No pic was every taken. How come?

Second question. I could not figure out which wb to use for HID headlights. They're not flourescent or tungsten. Its the kind of lighting you see on the lexus's/bmws/benz. Could someone help me with this?

When you take a shot using MLU you have to hit the shutter button twice.
The first time will lock the mirror up and the second time will expose the shot.

I don't know about HID lights but a workaround might be to shoot in RAW.
Then check which WB looks best in whatever RAW software you use and use that WB in future.

Hope that made sense.

Mirror lockup is a two step operation I believe. Once set the first shutter trip brings the mirror up and the second takes the photo.

HID lights? Don't know. Shoot a WB control. I use a piece of foam core for this.

And lomond obviously types faster than I do....

thanks for the help for MLU. I didn't realize it need two pushes of the button.

Now for the wb control, im going to be completely honest. Im horrible at figuring out this part of the wb equation. I''ll try a few raw shots tomorrow to see how things come out. I have RSE but still am trying to figure it out.

Shoot a picture of a plain piece of white paper under the lights being used/photographed and use that white paper to determine your WB in RSE. Use the eye-dropper selection tool in RSE (I assume it has this function) for WB and click the white paper. You should then be able to apply the same WB to other pictures taken in the same light.

Or just simply use Custom WB. (follow the user manual)