Autofocus motor in either camera or lens is important

Autofocus is the term for when a camera with his mechanics and electronics adjusts the lens different glass elements so that the desired subject becomes in focus. Today, when bying a camera and/or a lens, the autofocus function is often taken for granted but that has not always been the case and there are still things to watch out for.

On older cameras, there was no autofocus. The photographer had to adjust and focus manually with the focus ring on the lens. When the autofocus technology was introduced in the early 1980s, it quickly became a standard in the cameras and later on also the lenses.

Read more about the history of the autofocus on Wikipedia

When you, on a newer camera, press the shutter button halfway to focus, it's a motor in either your camera or lens that ensures that the lens elements move and align themselves to put the object in focus. The autofocus motor is either in the lens or the camera, sometimes in both. However, there are both lenses and cameras without an autofocus motor and would they be combined you as a photographer would have no possibility to autofocus.

If we look at these four products; two lenses and two cameras where one version has built-in autofocus motor and the other one has not.

Our test gear

Out of these products below we can all together get four different combinations.


Nikon AF 50mm f/1,4 D
  • Does not have a built-in AF motor

Nikon AF-S 50mm f/1,4 G
  • Has a built-in AF motor

Nikon D40
  • Does not have a built-in AF motor

Nikon D50
  • Has a built-in AF motor

Nikon AF 50mm f/1,4 D + Nikon D40


Nikon AF 50mm f/1,4 D
  • Does not have a built-in AF motor

Nikon D40
  • Does not have a built-in AF motor
  • Ouch! This combo do not support autofocus since neither the camera or lens have a built-in AF motor

Nikon AF-S 50mm f/1,4 G + Nikon D40


Nikon AF-S 50mm f/1,4 G
  • Has a built-in AF motor

Nikon D40
  • Does not have a built-in AF motor
  • Great! This combo will support autofocus since the lens has a built-in AF motor

Nikon AF 50mm f/1,4 D + Nikon D50


Nikon AF 50mm f/1,4 D
  • Does not have a built-in AF motor

Nikon D50
  • Has a built-in AF motor
  • Great! This combo will support autofocus since the camera has a built-in AF motor

Nikon AF-S 50mm f/1,4 G + Nikon D50


Nikon AF-S 50mm f/1,4 G
  • Has a built-in AF motor

Nikon D50
  • Has a built-in AF motor
  • Great! This combo will support autofocus since both the camera and the lens have a built-in AF motor

Importance of having an autofocus motor is clear

Of the four different combinations above, we can see that as long as there is a built-in autofocus motor in either the lens or the camera autofocus will be supported and work for you as a photographer. On Lensora, on each camera and lens product page, you will be able to see available and compatible lenses or cameras. We have avoided to display and present combinations of lenses and cameras that together wouldn't have the possibility to autofocus. If you go visit the page of Nikon AF 50mm f/1,4 D you will not see that Nikon D40 is listed as a compatible camera and the other way around, since both of them are missing an autofocus motor.