Perspective Control lenses for SLR cameras were developed primarily for architecture, interior, and still-life photography applications. PC lenses simulate some of the movements and control that photographers can get from a view camera. They are great for keeping lines parallel and subjects in focus. Just as PC lenses allow photographers to control what is in focus, they also allow you to control what goes out of focus and how quickly it does that. Fashion and portrait photos with enhanced bokeh or selective focus create dreamy blur and guide attention to the areas remaining in focus.
PC lenses or tilt and shift lenses have been around in various forms since the 1970. The Fuji GX-680 made a big splash in the 1980s as a medium format camera system with built-in bellows that could accommodate tilt and shift movements. Some fashion and portrait photographers jumped at the opportunity to play with selective focus. Both Nikon and Canon have recently made waves by announcing ultra-wide PC lenses, but it was the Canon TS-E 90mm and the Nikon 85mm PC-E lenses that brought tilt and shift to focal lengths more favorable to portrait and fashion photographers.
The tilt function of PC lenses allows a photographer to alter or tilt the plane of focus and decide which part of a scene they choose that plane to fall. For comparison, a traditional lens has a focus plane that is parallel to the film or digital sensor in the camera. The amount of depth of field is determined by the aperture of the lens and will give the image clear range focus 1/3 in front and 2/3s behind the exact point of focus. But when you alter the plane of focus using a PC lens away from parallel with the film or sensor, the area in focus can dramatically change.
The pair of images at top shows the same scene shot with two different lenses. The left image was shot with the Nikon 70-200mm zoom set at 100mm while the image on the right was shot with the Nikon 85mm PC-E. The right image and the image above show the effect of tilting the plane of focus on a horizontal axis leaving only the eyes in sharp focus. Since the current PC lenses are not made using bellows systems, they only tilt on a single axis as opposed to view cameras, but they can be rotated to accommodate a horizontal, vertical, or even diagonal axis.
Shifting the plane of focus on a vertical axis can also produce dreamy effects. As the focus plane shifts relative to the image plane, part of the focus plane draws closer to the camera while the other part shifts away from the camera. This has the effect of compressing the area in sharp focus of a standing subject, which is great to isolate attention on the face or eyes. However, that shift of plane might also have the unfavorable effect of rendering a background or foreground element in sharp focus that might compete for attention. It helps to envision how the new plane of focus cuts through a composition and what is added or subtracted from the focus.
These images show the same model shot at f/5.6 one with a traditional 105mm lens on left, and the 85mm PC-E lens on the right with vertical axis tilt which leaves a vertical zone of sharp focus on the model’s face and front of her dress, while her arms go quickly out of focus. By shifting the plane of focus clockwise to bring the right side of plane closer to the camera and the left side further, the background on the right side of the background falls to soft focus while the left side actually gains more focus than is see with the traditional lens shot.
As with any creative effect, a little can go a long way. I tend to prefer a moderate amount of tilt of the focus plane on my fashion shots. I have been able to incorporate this effect into several fashion shoots, but unfortunately not all attempts have made it in to the final product. The rapid shift of critical focus can obscure details on a garment that can be important to my clients. My favorite uses of the effect bring the audience attention to the face while creating a soft and dreamy feeling to the overall image. This effect can be simulated to a great degree in post processing with blur and bokeh filters, but I do like the control that comes from seeing the effect directly in a viewfinder.