Sometimes the autofocus on your lenses may not be exactly where you want it. Fortunately, it’s an easy fix as most modern cameras offer “micro adjustment” or “fine tune” option that lets you calibrate autofocus of attached lenses. You do need a calibration tool to do it, though. However, Karl Talyor offers you a simple calibration method without buying (or making) a special tool for it. In this video, he’ll show you how to do it for $0 and in just a few minutes. All you need is a few items that you already have at home.
You will need:
- A piece of whiteboard (I believe white paper will do as well)
- Two standard rulers
- A pen or a pencil
- The lens for calibrating
- Your camera on a tripod
Start by attaching the lens you want to calibrate onto your camera and set the camera on a tripod. In this video, Karl calibrates autofocus on a Canon lens and camera. However, the process is similar for most camera brands and lenses. I recently calibrated a Sigma Art lens on my Nikon D7000, and you can read more about calibrating Sigma Art lenses here.
Karl suggests that you open the lens as wide as it goes. He calibrates a Canon f/1.2mm lens in the video, so he opens the aperture all the way to f/1.2. This makes it easier to see exactly where the focus is.
When your camera is on the tripod, use a ruler to draw a line on your piece of whiteboard or paper. Draw a small line across it – this is where you’ll autofocus with your lens. Karl advises you to put the lens on manual focus, blur everything out, then switch it to autofocus and let it focus on the marked spot.
Now, put the two rulers on each side of the line. Put the same marking on both rulers on the focusing point. Take a photo, and then zoom it in to see where the focus actually is. If the image isn’t the sharpest at the focusing point you determined, the rulers will help you see where exactly the lens is focusing.
Now, find your camera’s “autofocus fine tune” in the menu. It’s different for every camera brand, but it should be easy to find in the Settings menu. Set the value depending on the difference between the focus point you determined and the actual point where your lens focuses. Take another photo and zoom it in to see if you did it right.
As I mentioned, I recently calibrated my new Sigma Art 18-35mm f/1.8 for Nikon. I figured out I was too lazy at the given moment to make a DIY calibration tool and I sure wasn’t gonna spend $60 on buying it. So, I did something similar to what Karl did. I fixed my camera with the lens onto a tripod and drew a line with a clear marking where I want the lens to focus and a few other markings behind and in front of it. I used the AF on the main marking and fine-tuned it in the camera settings. It took a few attempts, but it works like a charm now.
If you’ve never calibrated a lens before, this article will also be useful to learn how to do it, so check it out. Also, make sure to watch Karl’s video above to see what the setup and the process look like.