Editing shots taken using HiLite and Train

[CarlukeDave]

There have been a number of posts on the difference in colour between the train and the HiLite background and how difficult it is trying to evenly light the whole set up.

I am interested to know what methods people use to go from the white/grey difference to an even white background?

I have tried it myself, selecting the grey area and then adjusting the brightness, but it appears not to be the best way, I can't post any images at work but if it's not clear what I am trying to explain, I'll post an example later.

Dave