If you increase the luminance levels too much, the HDR would probably have wierd artifacts and such. I would suggest you get some good HDR software first. Photomatix is a good software and is very easy to learn to use.
Hey PrimePhotog, i'm actually already using photomatix, just bought it recently. I really like it but as can be seen clearly i'm still figuring my way around it thanks for the advice about the luminance, can't quite remember my settings for this particular tonemapping but i'll make sure i go easy on it in the future. It's one of those sliders where i'm still not altogether sure what it does haha.