Using old Nikon lenses on a new digital camera is one way to cut the cost of equipment. Older Nikon lenses often cost a fraction of the cost of a new autofocus lens of the same focal length and minimum aperture. Nikon has not made any significant changes to its lens mounting system since 1959, when the f-mount system was introduced. All Nikon lenses manufactured with automatic indexing, called AI lenses, can be used on Nikon digital cameras but may have to be focused manually depending on the camera body.
Determine the type of lens by looking at the back of the lens. Non-AI lenses will have a solid metal piece that looks like bat ears on the lens base and the black outer rim will be solid, according to AI Conversions. This lens cannot be mounted on some of Nikon’s newer camera bodies without damaging the camera. There are compatibility charts available online.
Mount the lens on the camera by lining up the dot on the lens with the dot on the camera and turning the lens counterclockwise.
Manually focus the lens by turning the focusing ring.
Set the camera in aperture priority mode. Aperture priority is designated by the “a” on the dial found on the left side of the top of most of Nikon’s digital SLR cameras.
Lock the aperture ring at the highest f-stop number.
Set the aperture you want with the camera dial. Bigger apertures (smaller f-stop numbers) will give you a blurred background because of a shallower depth of field. Smaller apertures (bigger f-stop numbers) will give you a greater depth of field.
Check the histogram, which is the graph that pops up on the LCD screen on the back of the camera after you take a picture, for correct exposure. If the graph is mostly to the left, the picture is underexposed. If the graph is mostly to the right, the picture is overexposed. To change the exposure, change the ISO or the aperture. To change the aperture, rotate the camera's control dial. The ISO is the camera sensor's sensitivity to light and similar to film speed in film cameras. Change the ISO by pushing the camera's ISO button and turning the control dial.
Non-AI lenses can be converted to make them mountable on all newer camera bodies.