How to calibrate the focus of a camera

Imagine a terrible situation - you've bought a new DSLR camera and the photos you take are not sharp. However, if you look closely at the images, you'll notice that the camera is focused, but completely on a different object, not the one you intended to focus on. In these cases, the focus shifts to the background (if it's behind the object, it's called "back focus") or conversely, closer to the foreground (if it's in front of an object, it's called "front focus"). Generally, people use the same term "background" for both phenomena, because even though we consider them opposites, in fact, they all remain the same phenomenon, as the autofocus missed the targeted area. Of course, such problems can also be due to other reasons. For example, the focused object or the camera may move, etc. But if the problem persists, contact the support center for a procedure called "Focus Calibration" or try to solve it yourself.

What is Back Focus?

Back focus is a consequence of inconsistent performance of different camera systems. This is usually related to an electronic issue, and the problem can originate from the camera, the lens, or both. Sometimes, with certain lenses, the phenomenon is noticeable, but not with others. However, this does not mean that the first lens was bad.

TDOWNLOAD Focus Chart !!!

HOW TO CHECK FOR FRONT AND REAR FOCUS ISSUES AND CALIBRATE THE LENS

You need printed focus chart, a good tripod, and enough room and light. It's better to do it outdoors, as there is a lot of light. Here are 5 steps to follow to check and calibrate your rear or front focus.
1. Print the test table in A4 format, then place it at 45 degrees, as shown in Figure 1. The height should be the same as your camera.
2. Then place your camera on a tripod and make sure it is parallel to a focus board. The distance between the camera and the focus board depends on the lens you are using. For example, for a 50mm lens on a full-frame/full-frame DSLR camera, the distance should be about 1.5 to 2 meters. If you use a wider lens, it should be closer. If longer, then further away from the focus table.
3. Set your camera to Aperture Priority mode and set to a maximum wide aperture (example: if you have a 50mm F1.4 lens put F1.4). It is also better to use self-timer mode to free the camera.
4. Turn off the image stabilization or vibration reduction mode in the lens if you have one.
5. Use only the unique central focus of your camera to make the focus and make sure the lens is directed to the center of the focus board.
6. Turn on the Automatic focus of your lens and focus on a thick black line in the middle of the focus board and take some pictures.
7. Check the test photos on your computer screen at 100% magnification to see if you have front or back focus.
8. To calibrate the lens for Nikon cameras, go to the "AF fine tune" in the menu. For Canon, it's "Microadustment"
Enjoy your sharp images!