Difference between a 50mm and 30mm lens?

I use Nikon and take a lot of artistic-portrait pictures. I like using low f-stops to get the shallow depth of field, but what would the difference between a 50mm lens and a 30mm lens be? Would one be better than the other, or is it just a matter of opinion?

The 30 and 50 are both normal range lenses if you have a DX camera go with the 35 mm 1.8 because of the crop factor that goes with the 50 or go with the 17-55 f2.8 if you need both 30 and 50. If you have an FX body id go with the 50 mm f 1.4 or f 1.8.

Although i don't use digital SLR I presume the lens on film and digital cameras are the same… So basically the longer the lens the shallower depth of field… A perfect lens for the type of shot you like ie portraits would be a medium length zoom… Something like a 35 mm to 100mm

Buy the one with the lowest f - stop. If it is the same then buy the 30mm.
I have a f1, 7 50mm lens, and is one of my person favorites! The only disadvantage (if you haven't full frame ) is if you don't want a close up, you have to shoot from distants. And that is why i suggest you the 30mm.
General i prefer the standar lenses better than zoom lenses. And i'm sure that you will be more than satisfiede with your new lens!

For portraiture go with the 50mm… On a crop sensor camera (DX) this will give slight telephoto effect which compresses perspective and will be flattering to the subject. You can't go wrong with a 50mm lens…
On a full frame camera (FX) 50mm is close to a normal lens ( 0 magnification - what the eye sees) but still makes a good lens for portraits even without the perspective compression.

Angle of view. 50mm would be narrower. On a full-frame camera, 50mm would be normal meaning the same as the angle of view of human eyes. On an APS-C camera, 30mm would be close to normal.

DOF. The longer the focal length, the shorter the DOF taking all other settings equal.

Which is better? It's not a matter of opinion. It's a matter of application, knowing what lens to use for what condition exactly.

http://keerok-photography.blogspot.com/2011/05/lenses-so-many-of-them-there-is-no-best.html