The very first thing I do when I get a new camera (after I enter the mandatory date/time information and my copyright, of course) is to adjust the diopter, that little wheel that you can turn next to your viewfinder. This lets you customize the sharpness of what you see through the viewfinder for your eyes. While it’s especially handy for people who wear glasses or contacts, adjusting your diopter is something everyone should do, as it will help you optimize what you see through the viewfinder.

Achieving the best results

When you think about it, adjusting your diopter is pretty easy. It’s even easier when you use one key accessory that helps you get the best results possible — your lens cap.

First, mount your camera to a tripod or put it on a flat, secure surface. This will alleviate any camera shake and will ultimately make it easier to adjust the diopter.

Put your camera on a tripod or flat surface so you don’t have to worry about camera shake and hand fatigue.

Then, put your lens cap on your lens. Press the shutter halfway down to activate the display in the viewfinder. With the cap on you’ll base your adjustments on the sharpness of the numbers and graphics, which works a lot better than looking for sharpness in a scene through the lens. Ultimately, adjusting the sharpness is much easier when just looking at the display, rather than being distracted by an image that may or may not be sharp.

With your lens cap on, focus the display with the diopter wheel getting the details sharp in your viewfinder, without the distraction of an outside image in front of the camera. Illustration by Serj Siz`kov, Adobe Stock

Finally, look into the viewfinder and start turning the diopter wheel. This typically features an adjustment range of -3 to +3, with the neutral level (0) representing 20/20 vision.

If you ever need to make adjustments down the road, the good news is that this isn’t a permanent setting on your camera — it’s something you can adjust any time.

What if it didn’t work?

While adjusting your diopter will certainly help in giving you optimal focus in your camera, if you need a larger or more specific adjustment, you might want to look into some correction eyepiece accessories that you can use with your camera.

Keep in mind that while adjusting your diopter will help you see clearly through the viewfinder, it won’t fix any autofocus issues or camera shake that you might be struggling with. The diopter is simply to help you see more clearly through your viewfinder.

Conclusion

If you’ve ever wondered why your images aren’t completely sharp when looking through the viewfinder, or if your eyes strain when at the image it shows, chances are the fix is adjusting the diopter to your eye.