Why and How to Use the Diopter Adjustment on Your DSLR Camera

Not all people have perfect 20/20 vision and that is why some of us wear glasses or contact lenses. People wearing glasses often find it difficult to look through the viewfinder with their glasses on as it tends to get in the way. But if they take off their glasses and look through the viewfinder chances are they’ll only see a very blurry picture. To help make photography a more enjoyable venture all major camera manufacturers have built in a diopter which can adjust the viewfinder image to compensate for your eye sight and thus help you see clearly when you look through the viewfinder without glasses.

Some Facts about DSLR Diopter

A properly calibrated diopter is critical to ensure precise focus especially when using manual focus.
Diopter adjustments has nothing to do with the lens focusing mechanism, it will only help you see the viewfinder image clearly.
When sharing your camera with another person the diopter needs to be adjusted to suit their vision and when you get back the camera you need to re-adjust the diopter to suit your eye sight.
The dioptre adjustment is a fully manual process and the setting cannot be locked.
There is no index point and nothing to tell you the level of correction entered.
Typically diopters in DSLR cameras have an adjustment range of -3 to +3, with 0 being nominal 20/20 vision.

Where is the Diopter Located in my DSLR?

DSLR Viewfinder Diopter

In case of mot DSLR cameras the diopter control is located near the upper right corner of the viewfinder. It is usually characterized by a +/- sign. In case of Nikon cameras the diopter adjustment wheel can be either big or small but regardless of its size it’s very noticeable. In case of Canon it is not very noticeable however it works just the same as in Nikons.

Calibrating the Diopter of Your DSLR Camera

What you are seeing through the viewfinder is the image from the lens projected onto a ground glass viewing screen you get to see the image sharpest when the diopter is correctly calibrated.

The easiest and most reliable method to calibrate the diopter of you DSLR camera is to point your camera at any featureless subject like a white wall, look through the viewfinder, turn your lens so that the wall is out of focus, now pay attention to the markings in the focusing screen and also to the various indicators in the viewfinder (your camera needs to be turned on and if you do not find any indicators gently tap your shutter button once)

Dslr Viewfinder on the left is un calibrated diopter and on the right is a calibrated diopter

Now turn the diopter adjustment wheel all the way towards the "+" side. The image will in most cases blurred (unless that is the right setting for your eye) slowly turn the diopter toward the "-" side until the lines and the viewfinder information becomes crystal clear.

You will find that there are more than one clicks where the image appears sharp so to get the best setting make sure you go past the sharpest view, and then back, so that you are sure that you have the best possible setting.

If you usually wear your glasses when taking photographs, make sure you wear them when setting the dioptric correction.

Going Beyond Standard Adjustments

Built in diopters can only adjust from -3 to + 3; those of you who have higher powers of short / far sightedness will need dioptric adjustment lenses that fit into the eyepiece of the camera which could go beyond the standard adjustments.

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