nalahm wrote:
Please give me advice lens filter that suit contax N glass , normally I used heliopan how about B+W nano , thanks
Based on your picture, you've got a nice matching lens hood for your Contax N. If you want the best filter, skip the filter and use the lens hood. For the cases where you really do want a filter (protective for blowing sand or salt spray, or a polarizer/ND for specific effects), if you already have a filter set that works for you, it's fine to stick with that. There's nothing special about Contax N glass that demands a different kind of filter from other lenses --- if you don't have problems from your current Heliopan filters, there's no need to rush out and buy the newest and greatest.