Perspective defines the spatial relationships between objects in a photo in respect to the viewpoint. How we perceive a scene all depends on which lens we are looking through, which then allows us to dial in camera settings and choose composition accordingly. So, why is it that we reach for one zoom lens over another, or maybe one prime over a telephoto? Often it’s perspective and compression or desired ‘distortion’.
A couple of weeks ago, this animation was posted on our Facebook page reaching over 200,000 people and garnering close to 1,000 likes. It lucidly illustrates the effects that certain lenses have, and what distortion they cause. This sparked an interesting discussion in the comments regarding which lenses photographers use for specific shots or compositions.
Combining our artistic abilities with our technical know-how, we reach into our bag of gear and pull out a lens that we think works best for the composition we are envisioning, but have you ever stopped to think about the qualities this lens is attributing to your image? We go over this in depth in Photography 101 we use entry level equipment to teach you the foundation of utilizing a range of zoom, telephoto, and fixed lenses to test their affects on composition, but here’s some key info you can use right now.
There are two types of distortion that may lead you to gravitate towards one lens over another: lens distortion and perspective distortion. These two concepts are often confused with each other because they both fluctuate based on distance. Perspective distortion deals with your close proximity to the subject. With anything in our field of vision, the closer it gets to our faces the larger it appears in relation to the objects behind it. The further you distance yourself the smaller objects will appear in relation to everything around them.
Lens Distortion & Lens Compression
While perspective distortion can be manipulated based on your distance to the subject, your lens of choice can determine additional distortion/affect compression. Let’s say you are using a 16-35mm f/2.8 (a popular and versatile choice) staying at a 16mm focal length. The image produced will naturally have distorted edges due to the wide angle, making objects appear wider when they are closer to the edge. While lens distortion is exaggerated on wider angles, it still exists at all focal lengths, just to a lesser degree. Meaning, just because you are using a 50mm prime doesn’t necessarily mean you are getting away without distortion
Similar to the caveat listed at the bottom of side-view mirrors on vehicles, lens compression simply means that background elements can appear closer to the subject than they actually are. We gravitate towards certain lenses that give us greater compression, such as a telephoto lens like a 70-200mm, to emphasize the effect. But here is where perspective comes into play: Using a 24-70mm wide angle lens can work the exact same way as the telephoto, it just depends on the distance between the subject and the background.
You can visualize this in the example images above: one taken on a Canon EF 17-40mm f/4L and the other on a Canon EF 70-200mm f/2.8L IS II USM. In the top image, shot at a 17mm focal length, our distance to the model is very close, but the distance between the background and the model is further. In the bottom image, shot at 200mm, we had to move further back because of the telephoto lens and our distance to the model increased, however, the distance between the model and the background remained the same but looks vastly more compressed than the top image.
Choosing one lens over another should be a calculated process and not based simply on wide apertures or compression qualities. Focus on your desired perspective and choose the lens that fits your vision for the image. Knowledge of how your gear works is a step towards strengthening your art and creating a signature style. For an in-depth understanding of the basics of photography and lenses, check out Photography 101 in the SLR Lounge Store, or sign up to be a SLR Premium Member and stream a wide array of workshops to further your photography knowledge.
For more information on how certain lenses affect distortion, compression, and composition, check out the Canon Lens War Series on SLR Lounge, for a visual comparison of a variety of lenses from the 16mm up to 300mm.