Many cameras feature a built-in adjustable diopter correction system, this means it's not necessary to attach an eyesight correction lens to the camera to adjust the diopter setting. Simply look at the focus indicators through the viewfinder and at the same time turn/slide the diopter adjustment knob, the correct setting is found when the focus indicators appear to be in focus and sharpest.
Be careful not to knock or poke your eye when performing this adjustment. It is only necessary to adjust this once but should be checked infrequently in case your eyesight has changed.
Most people will need to make a small adjustment, if you are far-sighted (need optical help to focus on nearby objects), you will need a '+' adjustment to bring the focus indicators into focus. If you are near-sighted, a '-' adjustment is required. If it is not possible to bring the viewfinder focus indicators into focus then you will require the additional viewfinder correction lenses see below. Most cameras with interchangeable lenses have a built-in diopter adjustment with a range of -2 to +1, adjusting this will allow some users to focus without their glasses (check your camera instruction manual for adjustment information).
In addition to the small amount of correction that is built into some cameras, it is also possible to attach an eyepiece correction lens. The table below shows which correction lens you need for your particular prescription. Please ask your nearest dealer for advice on what lens you should use with your camera and which they have available.
|Prescription||Nikon Correction Lens|
Cameras without eyepiece correction systems built-in, such as the FM3a have a -1 diopter setting as standard. In these cameras the viewfinder eyepiece supplied has no value and is plain glass and should not be confused with a correction lens. Use the above table to calculate the correct Nikon eyepiece for your prescription.
For older discontinued Nikon SLR cameras such as the F2 or Nikkomats, the Nikon F3 or FM2/FM3a eyepiece correction lenses may be used. The rubber viewfinder eyepiece of some cameras may need to be removed when using diopter adjustment lenses.