I recently bought my first "old"/used fixed style lens off ebay. Just got in the mail and I was SO exited to try it out. It's a 85mm Nikkor AF f1:1.8 D manual lens. I have a Nikon D7100 . I tried searching on the internet to see if this lens was even compatible and it seems it is. But I have no idea what I'm doing wrong. First I tried it on auto focus, then I changed the camera to manual focus and still nothing. It lets me focus manually from the lens, but the camera is acting like it doesn't recognize the lens and wont let me press the shutter button. Also, the letters f E E just flash on my screen in the upper right corner. This is the lens I purchased: Nikon AF Nikkor 85mm F 1 8D Excellent Condition with Original Accessories 0018208019311 | eBay In the auction He wrote " Please Note: This lens will only auto-focus with camera body which has auto-focus motor (D200, D300, D90, D7000.... and up) and will only do manual focus with D40, D40x, D5000 series, D3000 series... " So I figured since he mentioned above the d7000 and I have a D7100 it would auto focus. But if it didn't I was still ok, doing it in manual. I am wondering if there is some special setting in my camera I need to change so the camera will work with this lens? Let me know if I just bought a lens that isn't even compatible. I am going to be taking pictures of a friend's almost 1 year old, for his1 year old pictures,and was exited to try this one out on him ,but wanted to practice with it at home first. The other two lens I have are new up to date auto focus lenses.