I bought this adaptor to use my old Nikon (Nikkor) glass with a Fujifilm X-T1 I purchased expressly for that purpose. The adaptor works perfectly for this purpose. Connection is positive and firm. You may have to wiggle the lens just a bit to get a positive lock but this is true with Nikon bodies as well! I have used the adaptor with F mount and E series lenses and it performs all functions as advertised with the X mount Fuji body. Yes, the camera must be set in manual mode by the switch on the front of the body and in the menu "use without lens" must be set to "yes". It is also possible to use the camera in aperture priority mode with a manual lens. (you pick the f stop and the camera selects a shutter speed.It is so much fun to get the old glass out and shoot manually as in my old film days. While my old Nikon lens with work manually on my Nikon DSLR, the fiddle factor is too great to make it worth while. With a Fuji X-T1 or similar body all the manual controls are right there making using the old wonderful lenses that you paid high dollars for easy to use once again. This adaptor seems comparable to many I've looked at selling at a much higher price.A photo of the X-T1 with a Nikkor 50mm 1.4 pinned on is attached!