Nikon vs Canon lens for a Sony Nex 5?

Http://www.amazon.com/Nikon-55-200mm-VR-Vibration-Reduction/dp/B000O161X0/

vs

http://www.amazon.com/...0011NVMO8/

New or refurbished?

Looking to improve my zoom on my Sony Nex 5.

Neither? Why are you looking at Canon or Nikon lenses for a Sony? Neither will work properly with a Nex body. Why would they?

Maybe the Sony 55-200, or the Sony 18-200 for E mount, leaving out the adapter part altogether. At least a Sony lens adapted to the E mount will operate the way it is supposed to, neither the Canon or Nikon will work in any auto mode, won't autofocus, and probably won't meter properly. Waste of time and money to even try.

Why don't you just go with a Sony E mount lens that is specifically designed to be used with your camera? They make a number of E mount lenses… Such as the 55-210mm telephoto zoom lens…
http://store.sony.com/...1644718503

p.s. In your previous question you said you wanted a zoom lens for taking pictures at the beach. I must warn you to be very careful when using your camera at the beach, because sand (and water) will NOT be good for your lens at all. And if it's windy, expect sand to be blowing around freely and it could cause damage to your lens, particularly if you are zooming in and out and the lens is not weather sealed.

I agree

don't get Canon or Nikon lenses for your Sony, it's.well, insane to be honest. You will not have autofocus, no aperture control (on some lenses), and possibly no metering. Along with that, you will also lose 1-2 stops of light which will make the already rather slow lenses even slower.

Buy lenses specifically made for the NEX series cameras

Canon lenses are a non starter. No aperture communication, so wide open shots all the time.

Nikon AF-D lenses can be adapted, but will need to be used in manual focus and manual aperture modes. Nikon AF G lenses will not work, as with the canons they have a camera controlled electronic aperture.

I hate to sound rude, but as it sounds a little like you are a novice, your best best is either NEX lenses, or getting the alpha mount adaptor and using a sony or minolta AF lens (albeit with some caveats)

What? No Carl Zeiss?

Improve zoom? Use legs.

Neither. Although there are adapters available that will allow using a Canon or Nikon lens on your NEX-5 the reality is they really aren't worth the hassle. Manual focus, stop-down metering plus you have to be careful to choose a Nikon or Canon lens with an aperture ring - and neither of the lenses you're looking at has one. No aperture ring means no way to control the aperture - unless you are willing to spend as much or more on an adapter as either lens costs.

MTF has a Nikon G to Sony E adapter that has its own aperture for $375.95. You'll still have to manually focus the lens and use stop-down metering.

Bower has a Canon EF/EF-S to Sony E adapter that has its own aperture for $174.95. You'll still have to manually focus the lens and use stop-down metering.

The Sony E mount 18-200mm f3.5-6.3 zoom lens which is designed for the NEX-5 is $799.99.

Above prices from B&H - http://www.bhphotovideo.com/...ovideo.com

My advice is to save your money and buy the lens designed for your camera - the Sony 18-200mm
zoom.

NOTE: If you aren't sure what stop-down metering is just do a web search. Trust me, it isn't something you'll want to do once you learn what it is.