Tuesday, September 14, 2010
Focusing Is For The Birds • The Dark Side Of Long Exposures • Big Images From Small Files • To Tilt Or Not To TiltBig Images From Small Files
Q I came across your note in a previous column (Jan./Feb. 2010) about making large (40x40) prints of images captured with small cameras, such as an iPhone. How can you do that without losing much of the image clarity?
Via the Internet
A Well, it’s not about clarity. It’s about creativity. You can’t maintain the detailed information in a small iPhone capture if you enlarge it very much at all. If you do, the pixels themselves become a prominent part of the final image. The iPhone used for Dewitt Jones’ great images (referred to in the earlier column) has only 2 megapixels, enough for use on the phone’s small screen and to view in small sizes on a computer monitor. (Even if Dewitt has upgraded to the new iPhone, he still has only 5 megapixels.) To create a large-format print from an iPhone file, you need to move far from your original capture by processing and “tweaking” it a number of times. First, add special effects using apps in the iPhone (such as Photogene, Photo fx or CameraBag, to name a few), then interpolate the image to new dimensions and add even more layers of creative manipulation and give a painterly look with software such as the Topaz Clean and Simplify plug-ins for Photoshop. The file becomes a new photograph loosely based upon the basic forms and colors of the original.
Why would you do this? Because you can! No, that’s not the only reason. You probably take your iPhone everywhere you go, and even if you don’t have cell service, you still can use it to take advantage of an unexpected photo opportunity. If you have colors and shapes, you have your starting point. But if you want true, absolute, tack-sharp, high-resolution detail in a big print, you still have to capture it with a professional-level DSLR and high-quality lens, using all the techniques and equipment required to eliminate blur and gather as much detail as possible.
To Tilt Or Not To Tilt
Q I stumbled upon an article on Ansel Adams on the OP website (see “Shoot Like Ansel Adams With 35mm DSLRs,” 6/1/2008). A few of your photos were used as examples, using a tilt/shift lens for landscapes. What’s the advantage of a tilt/shift over shooting at a smaller aperture? Would it be worth investing in a tilt/shift for landscape photography?
Via the Internet
A A tilt/shift lens has front elements that can be tilted, which changes the plane of focus to more efficiently apply depth of field (the range of sharp focus) across a landscape. (If you want to know more about how and why this works, research the Scheimpflug Principle.) Used to maximum advantage, a tilt/shift lens can render a scene sharp from close foreground to distant background, as when photographing a field of flowers in an alpine meadow ringed by high mountain peaks. This apparent increase in depth of field can be achieved even with larger apertures, allowing shutter speeds fast enough to stop the movement of vegetation in a landscape. The use of very small apertures to achieve the same depth of field may compromise sharpness due to diffraction and/or movement of the subject or camera being emphasized by slow shutter speeds.
Tilt/shift lenses from Nikon and Canon come in a wide range of focal lengths, from 135mm to an ultra-wide 17mm. They’re expensive, but very useful for landscape photographers. I carry at least two tilt/shift lenses, the 90mm and 24mm Canons, when concentrating on scenic images.
The tilt/shift lens is useful in other ways, too. The shift aspect of the tilt/shift lens works to overcome vertical distortion (often a problem in architectural photography) and to capture three-image panoramas across the image plane.
Should you buy one? It depends on how serious you are about your landscape photography. There are other ways of increasing depth of field with any of your lenses (if there’s no movement occurring within the scene). You can take multiple images with different focus planes by moving through the subject from near to far and capturing slices of overlapping areas of focus. These multiple images can be assembled in either Photoshop CS5 or the stand-alone program Helicon Focus. The multiple-image composite technique enables virtually unlimited sharpness under ideal conditions, whereas the tilt/shift lens may solve depth-of-field problems in windy conditions as well. [Editor’s Note: An article by Willard Clay in this issue of OP describes several techniques for shooting and combining multiple images to achieve deep focus.]
For information about upcoming seminars and digital-imaging workshops, visit www.georgelepp.com. If you have any tips or questions, address them to: OUTDOOR PHOTOGRAPHER, Dept. TT, George Lepp, 12121 Wilshire Blvd., Suite 1200, Los Angeles, CA 90025-1176 or online at www.georgelepp.com.
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