The distortion in your video may irritate you when you're working on the video's edit. When you take images or record sound, you frequently end up with distorted results due to lens distortion. In this article, we will discuss what lens distortion is, how it may be fixed, and the factors you need to pay attention to avoid lens distortion when taking or recording videos.
In this article
Part 1: Basic introduction to lens distortion
1. What is lens distortion
Distortion means that the straight rectilinear projection is not straight. In the pinhole camera model, lens distortion is measured by how far from the image's ideal projection is. From a geometric optics point of view, the scene's straight lines don't look straight in the image.
When you take a picture, the camera lens can somehow change the shape of the image. It is called camera lens distortion. In simple terms, we can tell you that this is the case because distortion in-camera is when the lens makes curved lines in an image and doesn't show the straight lines from the scene.
2. What cause it
Lens distortion happens with all lenses. It is because of several things, such as how the lens is curved, how far away the subject is, and the angle at which the photo was taken. Furthermore, it changes the image in many ways, but you can see it most when straight lines at the frame's edges are no longer parallel.
Most geometric lens distortions happen when the focal distance is short (barrel distortion), long (pincushion distortion), or when a fish-eye lens is used to take a picture from a low angle (keystone distortion).
Part 2: How to correct a distorted lens?
A lot of times, with lower-end wide-angle lenses, especially action cams like GoPro, you get pretty gnarly distortion when you're filming. As we know, the Earth is round, but it shouldn't look like this when you take a picture. Indeed, it's very distorted, it has the horizon line bending all over the place, and basically, all of the lines in the video have some level of curvature.
Hence, follow all the steps below to know how to fix it:
Step1 Import your video to Filmora.
Step2 Click on the clip and head over to the lens correction. Choose the "Camera model" based on what you used, but in this tutorial, the video was taken with a GoPro Hero 7. However, you can choose some other camera model options there.
Step3 To adjust the distortion, you can slide the bar to the left or the right. If you slide the bar to the right (maximum level), there will be no adjustment. However, if you slide the bar to the left, you can see it pulling those lines as high up as possible.
You can see a bit of curvature, but it looks much more natural, and all of the lines in the video look so much better.
Step4 Lastly, if you play the video back, you will see the video look much better than before.
Part 3: How to avoid distorted lens while shooting?
1. Avoid very wide-angle lenses
The more distortion there is in a lens, like a 15mm prime, the wider it is. Sometimes you need a very wide-angle lens, and distortion is unavoidable. If you have room to move back, you could try using a lens with a different focal length.
2. Avoid getting too close
Doing so will enhance optical distortion in many lenses and the likelihood of perspective distortion in all lenses.
3. Be mindful of your composition
There are numerous instances where distortion is acceptable or even intended. Others must be carefully examined, such as utilizing a wide-angle lens to photograph a row of people. When you get too close to a group, the distortion makes the people at each end appear considerably wider! Therefore, consider your composition. Stand back and add space around your group; if necessary, you can trim the image afterward.
4. Use a 50mm lens
50mm lenses are often called "all-purpose" lenses. There is a good reason
for this. A 50mm lens is great for portraits, street photography, and many other kinds of photography, including architecture. If your subject is big, you just need space to stand back. You will see that a 50mm lens rarely distorts the image.