Difference between 10-18 lens and 16 lens with adapters

Dennishh wrote:

The 10-18 is a high quality lens with optical stabilization that is better in almost all aspects and the 16 mm with adapter. I have shot the 16 F2.8 with the wide-angle adapter and gotten some very good results at F8. Edge sharpness is a problem with this combination whereas I don't see edge sharpness problems with the 10-18. The ability to zoom is another feature that sets it apart also it is wider by 2 mm than the 16mm with adapter.