Have you ever wondered why despite your best efforts, your subject looks disproportioned in certain images compared to real life? Have you wondered why some buildings look like they are tipping in images? Chances are you are dealing with lens distortion.
The fact is that all lenses, irrespective of how expensive they are, have some distortion. However, there is a workaround you can use to ensure you find the perfect portrait lens and avoid ugly distortions.
What is Lens Distortion Anyway?
Lens distortion simply means the distortion of the original view of the subject in a photograph. When this happens, the lines which are straight in real life now become skewed outward in a photograph.
Lens distortion is mostly as a result of lens optics. It is known that the wider the lens, the greater the distortion. For instance, you will notice that images taken with a fisheye lens have major distortion due to the fact that fisheye lens has a very wide angle. When you are learning about distortion in photography, it is important that you understand that the closer you are to the subject, the more pronounced your distortion will be at any focal length.
Types of Distortions
There are various types of distortion and they include:
- Wide-angle Distortion
This type of distortion is caused by using a wide-angle lens. Like I stated above, the wider-angled the lens, the more curved that straight lines will appear.
- Barrel Distortion
Barrel distortion can be easily seen when you are working with wide angle lens. Generally, when this type of distortion occurs, you will notice straight lens at the edges of the picture "bowing out" just like a shape of a barrel. This type of distortion is very obvious in fisheye lenses and it helps give them their distinctive look.
- Pincushion Distortion
Pincushion distortion is another notable type of distortion. It is normally seen when you are using longer telephoto lenses. Here, the lines do the opposite and bend inwards. In most cases, it is difficult to spot this effect. However, it becomes very obvious when you are shooting a rectangular shape like a window frame.
- Chromatic Aberration
Lens distortion is not just about the distortion to the shapes of objects, lines, and edges. It can also cause fringing. When you use a cheap and nasty lens and zoom for some edges, you may end up with color fringing or chromatic aberration. Chromatic aberration is harder to spot when you use more conservative focal lengths.
What Should I Know About Lens Distortion?
Anyone can identify distortions in photographs. If you are using a wide angle lens and include all or even parts of your subject's body in a portrait, the result is most likely to be a "bobble head" appearance of the subject. Moreover, this is made worse by the fact that you have to get close to your subject when you using a wide lens compared to the distance you would require when you are using a longer lens.
You can get much less distortion when you use a longer lens. There are so many benefits of using longer lenses as far as distortion is concerned. The first benefit is that you won't have to get very close to your subject as you would when using a wide lens. Secondly, longer lenses add "lens compression" - this simply means that instead of widening features, they flatten it. Of course, this is a desirable feature.
Should I Only Use Long Lenses for Portraits?
No, you don't have to use only long lenses for portraits. The fact is that there are no “perfect portrait” lenses for avoiding distortion entirely. The trick lies in understanding the effects of wide angle lenses and learning when you should or avoid using wide angle lenses.
There are some reasons why you will need wide angle lens to shoot portraits. Some photographers will use wider angles to slim their subjects, especially when a part of their body such as head appears somewhat larger for other parts of the body. Certainly, learning when to use wide angle lens for a portrait to avoid distortions requires a lot of practice.
What Do You Mean By Lens Compression?
I talked about lens compression above, i.e. when you are using longer lenses. This simply means that longer lenses come with optics that allows them to flatten the features of your subjects and bring background closer. The background element may not be so obvious when you are in a studio setting. However, when you are shooting outside, you will notice that the background of the portrait shot with a longer lens will be closer to the subject than the one shot with a wide angle lens.
How Should I Avoid Lens Distortion?
The truth is that you may not be able to completely eradicate lens distortion. However, having a good range of lenses will save you a lot of stress.
You will get a good result when you use prime lenses. They tend to reveal less distortion. Prime lenses such as 50mm and 85mm tend to have constant wide apertures which make them great for portrait and easier for fixing lens distortion in software. You can get these lenses online.
Alternatively, you can use Lightroom's Lens Correction tool to correct these effects. Reduce or eliminate chromatic aberration with the use of Basic tab (in Lightroom) or make use of the Manual option to achieve a finer degree of control over horizontal and vertical distortion, scale, and other parameters.
Note that you can easily distort people in an image when you are trying to straighten the edges of buildings behind them. You need to be careful when you are working on the images using photo editing softwares.
So What Are the Perfect Portrait Lens?
Like I stated above, there are no such things as "the perfect portrait" lens, it will take a lot of learning to master the lens you need and when to use them. Moreover, the type of lens you need will be influenced by factors such as shooting with a crop sensor or a full frame, your location, and of course, style. Ideally, I will recommend using 85mm when shooting indoors and 135mm when shooting outdoors. Your style may be different; you just need to figure out what works best for you.