1. Canon DSLR mount(Canon DSLRs, e.g. Rebel Series, 700D 650D 600D 550D 7D 60D 7D etc) is called EF, usually expressed by EOS, and Canon mirrorless camera(Canon EOS-M mirrorless cameras like M1 M2 M3) was usually expressed by EOS M
2. Nikon DSLR mount(Nikon DSLRs, e.g. D40 D70 D3100 D3200 D3300 D5100 D5200 D5100 D7100 etc) is called AI or F, usually expressed by Nikon/AI, and Nikon mirrorless camera(Nikon 1 series mirrorless cameras like N1 1 V1 V2 V3 S1 S2 J1 J2 J3 J4 AW1 ect) was usually expressed by Nikon1

If your camera indicated "lens is not properly installed", please modify the camera menu settings. Usually called the "release the shutter the lens is not installed", you can modify the settings to allow. Specifically refer to the camera manual.Following are some examples:

1. MFT（M4/3 mount camera）'Lens Not Found' - Warning Message Appears
   For Panasonic Lumix:
   The camera needs to be set to function without a MFT-Mount lens attached. You can do this by changing the following camera setting:
   'Menu' -> 'Custom Menu 5' -> 'Shoot W/O Lens' -> 'On'
   (Exact naming and location of this option may change depending on camera model)
   
2. Fujifilm X mount camera, The camera needs to be set to function without a GFX-Mount lens attached. You can do this by changing the following camera setting:
   'MENU' -> 'SETUP' -> 'BUTTON/DIAL SETTING' -> 'SHOOT WITHOUT LENS' -> 'ON' (Exact naming and location of this option may change depending on camera model) Choose ON to enable the shutter release when no lens is attached.
   
3. Sony E mount camera, 'No Lens Attached' - Warning Message Appears
   The camera needs to be set to function without a E-Mount lens attached. You can do this by changing the following camera setting:'Menu' -> 'Setup' -> 'Release w/o Lens' -> 'Enable'
   (Exact naming and location of this option may change depending on camera model)
   
4. Nikon 1-Series mirrorless camera , 'Check lens. Pictures can only be taken when a lens is attached' - Warning Message Appears
   With a Nikon 1-Series camera (such as the J2), you will need to make sure the camera is in 'Manual' exposure or shooting mode and the focus selection is also set to manual. When in any other mode the camera tries to take control of the lens which is not possible as the adapter does not have any contact with the camera circuitry, so you get the lens check warning as the camera does not think there is a lens attached.
   
5. 'EOS M mirrorless camera ,'No Lens Attached' - Warning Message Appears
   The camera needs to be set to function without a EF-M Mount lens attached. You can do this by changing the following camera setting:
   'Menu' -> 'Custom Menu' -> 'Custom Function 7' -> Select 'Release shutter w/o lens'
   (Exact naming and location of this option may change depending on camera model)
   
6. Konica Minolta:
   For Konica Minolta and "No Lens Attached"
   Custom Menu 3
   First item "Shutter Lock"
   Set it to "Off: no lens"
   (Depending on camera model "Shutter Lock" May be in different menu location)
   
7. 'Samsung NX 'No lens.' - Warning Message Appears
   The adapter is designed to trigger a sensor inside the camera body itself so no setting needs to be changed. If the error message is coming up with one of our adapters attached, then it is possible that the adapter is not hitting that sensor the way that it should. Usually rotating the adapter slightly in the mount, or un-mounting and remounting the adapter clears the problem with no further action needed. If that doesn't solve the problem, then the best course of action would be to swap out the adapter you have with a replacement.