It really depends on your level of lucidity and realism (and recall of the dream as well!). Sometimes when I go lucid things like... radiate and get much more real. It can get as real as how you feel when you are reading this, or can be as fuzzy as you imagining flying right now .

Check this out that I wrote

http://www.dreamviews.com/forum/viewtopic.php?t=11037

Sometimes it feels to me like a dream's realism is kind of set from the beginning. I've had somewhat real ones and how real it is kind of is consistent throughout. But with certain methods your dreams can become a lot more real!