http://www.nikonchat.com/35mm-1-8-nikkor/

Is it okay if I changed my Nikkor 55-200mm f/4-5.6 with 50 mm f / 1.8?
because I rarely use my 55-200mm and I'm not really much in the zoom or something .. and what I like about the 50 mm depth of field is .. of course i would love º 35 mm f / 1.8, but its more expensive than my 55-200mm .. What do you think? I mean 50 mm depth of field (blurred backgrounds, bokeh, etc.) I have a D40, if not 50 mm autofocus on the D40, you can still? manual focus is easy? my 55-200m is the VR version
The 50 mm f / 1.8 is a good quality lens recommended by many users. Manual focus can be achieved a bit difficult at its maximum aperture, since the viewfinder is not able to show the depth of field is small. If you stop to f / 2.8, which should not problems. If you practice manually focusing on the maximum aperture, it should not pose a problem.
Sunday Walk…..GH2 Footage with Nikkor 35mm 1.8