What is a Diopter, and how do I set it?

If you’ve ever wondered what that tiny dial attached to the outside of your viewfinder is, the one with the little +/- on it, well, you wouldn’t be alone. I’m constantly amazed by how few people actually take the time to make sure this is set correctly. The good thing is even if your diopter is completely out of whack it usually won’t have an impact on the outcome of your image.

So what is a diopter, and why is it important?

“A diopter is a setting on your camera body that adjusts the image in the viewfinder to match your eyesight.”

So what this cool little dial does is that it makes sure that the image you see inside the viewfinder, along with all of the setting text that is displayed  in there as well. Pretty important I’d say! It is relatively easy to bump this wheel on accident and then your wondering why the image you’re seeing isn’t in focus even though the lens says it is.

Take the time to make sure this is set correctly every time you get out to shoot your camera. It only takes a second to test it out! The easiest way I have found to make sure it is tack sharp is to do the following:

1) Make sure your lens cap is ON you lens, so you only see black through your viewfinder.

2) Look through the viewfinder and “wake up” your camera so that your screen settings appear (you may have to repeatedly wake the camera up during the rest of the process)

3) Move the diopter wheel all the way to one side until it stops. Your display should be moderately blurry at this point.

4) Move the diopter wheel back toward the center until the number and settings inside your viewfinder look tack sharp

5) Always go a couple of clicks past where you think it looks good until it starts to blur out again and then come back. This will just make sure that you’ve hit the sweet spot!

6 (optional) Make note of where the mark on the dial lines up just in case you ever bump it in the future.

 I made a video that shows in pretty good detail how to do this, and even though it is several years old it still holds true today. Every time I get a new contact prescription or glasses I always make sure my diopter is dialed in correctly. If you have even just a little less than perfect vision, but don’t wear any correction this is a huge feature. There is a good chance you’re just used to the default (center value) setting on the diopter and may not think there is anything you can do to get it just right. Well there is!

If you are someone who wears glasses then you know how annoying it can be to look into a viewfinder with them on. Using the diopter adjustments, you can actually set the viewfinder for your natural vision without your glasses so that you can shoot without them and still be able to see a clear picture inside the camera! However, if your vision is pretty bad I wouldn’t recommend it, because as soon as you look up from the camera you’re going to need your glasses back. But, for someone with just a mild correction who can get away with or without glasses, this is perfect for you!