For many years, 35mm camera users have often been able to safely ignore the subject of camera movements. Not so for the large format folks, the relatively large film plane of a 4×5 view camera requires photographers to go to lengths even in the simplest images to get a deep depth-of-field, lengths that often include both camera movements and enormously tiny apertures (e.g., f/64). Our smaller film (or digital sensor) areas come along with a comparatively deeper depth of field. For better or worse, we may not wish to maintain our ignorance much longer.
If, like many photographers, you keep a close eye on gear announcements, you’ll have noticed the trend. While Canon had been selling three tilt-shift lenses for years, more recently they updated the 24mm tilt-shift with the ::amazon(“B001TDL2O0″,”Canon TS-E 24mm f/3.5L II “):: (greatly improving it’s optical quality) and added a ::amazon(“Canon TS-E 17mm f/4L”,”17mm”):: to the lineup. In the same time frame, Nikon announced and began to ship ::amazon(“B0013BEEUW”,”24mm”)::, ::amazon(“B001BTG3NW”,”45mm”):: and ::amazon(“B001BTAZHM”,”85mm”)::. What’s behind this new excitement?
I believe one of the primary drivers of this new life is the increasing resolution of digital cameras. With three DSLR manufacturers now producing cameras with over 20 megapixels, the hurdle for “enough” depth-of-field has gotten higher and higher. The traditional solution of simply using a smaller and smaller aperture (that is, a bigger and bigger f-number) has become less and less appealing, too, as that effect (which blurs images more and more for very small aperture openings) becomes more objectionable at higher resolutions. So, what’s a photographer to do?
The large-format guys folks among you already know the answer. While we small-format folks often think of depth of field and focus distance in terms of distance from the camera, it isn’t required (as a matter of optical physics) that the “focal plane” of a lens be perpendicular to the direction the camera is looking in. It is possible, quite possible, to tilt the focus plane in useful ways using the “tilt” camera movement on a tilt-shift lens. If your scene (and this is a big “if”) falls primarily along a plane, such as a flat landscape of low flowers, it’s possible to adjust the focus plane to put the whole field of flowers, from near to infinity, “near” the focus plane. This allows you to keep everything in focus with the lens at a larger aperture (lower f-number, smaller depth-of-field) and keep everything sharp. As a bonus, you’ll also end up with a faster shutter speed, which may help keep those flowers from blurring in the wind.
The advent of LiveView has been a real boon to photographers wishing to use tilt-shift technologies as well. It is often incredibly difficult to adjust the non-intuitive controls of a tilt-shift lens with an optical viewfinder. Modern electronic viewfinders that allow one (on a tripod) to spend time zooming into different areas of an image enable far more precise placement of the plane of focus.
While I believe that using tilt to improve (apparent) depth-of-field is the primary reason we’re seeing more of these lenses, it’s not the only reason. It’s possible to use the same effect to reduce the apparent depth of field, rather than to increase it, an effect which many folks are now leveraging to create faux “miniatures”. Also, shift movements can be incredibly valuable for perspective correction, as well as having additional uses in shooting for panoramic stitching and architectural work.
While pricey (most of these lenses are in the $1500-$3000 range) and challenging to use, we’ll be seeing more and more of these lenses in the coming years as a part of the never-ending quest for photographic perfection. In an upcoming post (probably late this week), I’ll give you a quick demonstration of what these wonders can accomplish.