On <http://www.nextcomputers.org/forums/viewtopic.php?t=2044> someone
adjusted his megapixel to show a bright picture after that.
My experience is, if the tube is dark, you can't adjust that. But you
can convincing yourself:
Adjusting is easy to do, you have to remove the cover. You need a
plastic adjustment screwdriver set. The holes for adjusting points are
describted.
If it won't work, maybe this adapter is an option:
<http://www.nextcomputers.org/forums/viewtopic.php?t=2044>
And of course eBay, blackhole sells megapixels for about ~$50.