Hello, I am interesting in buying some Nikon manual focus lenses, focal lengths of 20mm, 24mm, 28mm, and perhaps 35mm. I haven't decided which versions to get (f/2 or f/2.8 where applicable) but I want ones that come with the close focusing system (CRC?) if they were made with that. Problem is, I dont know how to identify which lens should have this. I am in Shanghai China, and buying at 2nd hand stores where there is virtually no English. Can anyone give me pointers as to how I might identify which version of these lenses that I might come across? Also, can I assume that if they have the rabbit ears clip on them, that they are AIS lenses? Thank you for any tips.