samiramis wrote:I am a bad photographer but do you talented people use live view with canon camera or look in viewfinder and take the photo?
When will you use live view and when will you not use it and why?
"Talented" may be stretching it in my case but I'll give you an answer anyway.
The main advantages of Live View seems to be twofold:
(a) When you want to take shots unobtrusively, such as candids. For example,
http://www.pbase.com/akmc_in_au/image/99805453/original(b) When you simply can't contort yourself around sufficiently to get your eye to the viewfinder. For example, there's a lookout on the road between Sydney and Canberra. The last time I was there I had to elevate the camera so far up on the tripod to get a view over the barrier that there was no way on earth I could possibly see what I was shooting, and had to make a best guess as I had only my 300D at the time. If I'd had the 40D with me, I'd have been able to get some decent framing on the shots.
The major "downside" (though whether this is really a downside or not is in the eye of the beholder) is that because of the way Live View works you can't rely on auto-focussing; you'll need to do it manually. However on cameras which have reasonably sized screens (such as my 40D), that's not all that difficult to do.
As an extension of point (b), the Canon Live View software can also be used so that you can "look" through the lens via (say) your computer notebook's monitor. Granted this won't be something that you'll be doing often, and very rarely outdoors, but it does aid you if you're doing self portraiture, for example. I've played around with that, though I haven't done any shots that are "keepers". However self portraiture is a pain to do for most people I think (there are a few PBasers who are remarkably good at it), so every advantage that you can give yourself will help.
Other than (a) or (b) above, though, I'd tend to stick with the viewfinder.