IF THE CAMERA SENSOR IS THE CANVAS, THEN THE LENS IS THE PAINTBRUSH.

A lens is the eyeball of the camera and is therefore the single most influential factor when rendering the image.

The light passes through the lens and onto the cinema camera sensor. During that process, the light is refracted by the lens coatings as it passes through all the elements and groups of elements until it reaches the aperture blades then hits the image sensor. The lens therefore effects all of the following attributes of the image that are not related to camera sensor performance:

Color Rendition and Contrast through Coatings

The coatings of the lens influence the way color and contrast is rendered. Different lens manufacturers strive to achieve a certain look and consistency with their coatings on how the lenses depict color and skin tones. Cooke is perhaps the most famous example with its “Cooke Look” and storied history of delivering warm colors, high contrast, and flattering skin tones for more than 100 years.

Focus Roll Off

Focus roll off can be described as smooth or harsh and also influences how the bokeh (out of focus area) is rendered. Ideally, the focus rolls off smoothly from critical focus to soft focus to create a smooth and pleasing image. If the focus roll off is harsh, it may look as if it was shot on a green screen and composited. Smooth focus roll off blends the image together and makes focus pulls smooth and less jarring. If lens elements are misaligned, chromatic aberration becomes apparent. For some vintage style lenses, chromatic aberration is a creative choice and adds life to the lens. In general, most people don’t like the look of chromatic aberration because it gives the subject of your focus cyan, green, or magenta edges. However, I must admit, on some lenses, when done well and purposely, it actually can be a nice look.

Focus Fall Off

Focus fall off can be seen in how the critical focus is rendered from the sweet spot of the lens (the center) to the outer edges. Some lens manufacturers strive for optimal edge to edge sharpness, such as Zeiss. Other manufacturers and most anamorphic lenses have a gradual fall off and can be quite soft outside the center. Like many aspects of lenses, focus fall off is subjective. Some cinematographers love crisp edge-to-edge sharpness so they can focus anywhere within the frame, while others prefer softer edges for a creamier and dreamier look.

Distortion

All lenses distort, because that’s just physics. Typically, higher end lenses will minimize distortion as much as possible so the image stays flat as the camera pans, tilts, and moves through space. Anamorphic lenses might distort in a strange wavy manner, called mumps, which is an undesirable trait. In general, the wider angle the lens is, the more difficult it is for lens manufacturers to control distortion, particularly at the edges of the frame. Most cinematographers prefer minimal distortion, but it can be a creative choice to use a lens that has more distortion; such as a fisheye lens.

Vignetting

Vignetting is the gradual darkening of the image from the center to the outer edges. The center of the lens is always the brightest because all the light is being focused on that region. Lens manufacturers strive to enhance lens coverage and create the fastest (most light transmitting) lenses possible with the largest image circles to minimize vignetting and maximize sensor coverage. All of these benefits typically come with the tradeoff of more size and weight because when it comes to optics, it’s always a tradeoff with physics in any of these categories.

Bokeh

Bokeh is the out of focus area of the image. Bokeh is life. It’s not just blur, it reacts and responds to the light, has color, texture, shape, size, and uniqueness. Lens manufacturers are able to achieve different characteristics within their bokeh to establish a certain look. For example, Leica is famous for their painterly textured bokeh. In general, the wider the aperture, the more bokeh is maximized since the depth of field is decreased, which makes more of the image out of focus. When I shoot, I’m always on the hunt for capturing the most beautiful bokeh and I’m always thinking about ways to maximize the effect. Sometimes, the bokeh itself tells the story and the shot doesn’t need to be in focus at all. Most of the time, I’ll try to at least ensure one element of the shot is in focus or I will begin out of focus and rack into the subject. I also enjoy setting the focus and then having my subject move into it or move through it so you can watch the bokeh react as the focus rolls off of the subject.

Flares

Every lens flares differently. Flares have many characteristics such as color, softness, orbs, shape, and haze. I love a good lens flare and I appreciate many different styles. Anamorphic flares are famous for their horizontal reaches and classic blue color. Many anamorphics can flare to the color of the source light. My Xelmus Apollo anamorphics have a legendary flare that changes color to the source, incorporates elliptical rainbows, and depicts lots of orbs. Orbs are a reflection of lens elements that appear in the flare and add a three-dimensional effect to the flare. The lens coatings greatly impact the color, sharpness, and sensitivity of the flare and also determine how much the lens hazes. My Zeiss Supreme Radiance lenses have an astonishing ability to reject haze, maximize contrast, and yet still produce a pronounced and orb-rich vintage blue flare, even wide open at aperture T1.5. Most lenses at T1.5 will haze over the instant you point it at the sun or shine a bright light into them. For these lenses, the flare is benefited by stopping down the aperture to help control the light, which you will see me do during my lens tests.

Now that you have some background into what makes lenses amazing and unique, and why I conduct my lens tests in the manner that I do, peruse through my BP40 CREATIVE Lens Test videos so you can see with your own eyes how some of the world’s best full frame cinema lenses perform in a real-world scenario.