Introduction
This is my follow-up article on the basics of photography. I have been an recreational photographer for most of my life and with the growing accessibility of digital photography I thought it would be the perfect time to share some knowledge. In this installment I would like to introduce several different types of photography. Each of these topics could be a post in itself but I hope this introduction peeks your interest and you search out and try any or all of the styles described below.
Macro
The classical definition is that the image projected on the “film plane” (i.e., film or a digital sensor) is close to the same size as the subject. Most 35mm format macro lenses achieve at least 1:2, that is to say, the image on the film is 1/2 the size of the object being photographed. Another important distinction is that lenses designed for macro are usually at their sharpest at macro focus distances and are not quite as sharp at other focus distances.
Limited depth of field is an important consideration in macro photography. This makes it essential to focus critically on the most important part of the subject, as elements that are even a millimetre closer or farther from the focal plane might be noticeably blurry.
Tilt-Shift
“Tilt-shift” actually encompasses two different types of movements: rotation of the lens relative to the image plane, called tilt, and movement of the lens parallel to the image plane, called shift. Tilt is used to control the orientation of the plane of focus (PoF), and hence the part of an image that appears sharp; it makes use of the Scheimpflug Principle. Shift is used to change the line of sight while avoiding the convergence of parallel lines, as when photographing tall buildings.
Scheimpflug Principle
The principle is named after Austrian army Captain Theodor Scheimpflug, who used it in devising a systematic method and apparatus for correcting perspective distortion in aerial photographs. Normally, the lens and image (film or sensor) planes of a camera are parallel, and the plane of focs (PoF) is parallel to the lens and image planes. If a planar subject (such as the side of a building) is also parallel to the image plane, it can coincide with the PoF, and the entire subject can be rendered sharply. If the subject plane is not parallel to the image plane, it will be in focus only along a line where it intersects the PoF.
HDR
High Dynamic Range Imaging (HDRI or just HDR) is a set of techniques that allows a greater dynamic range of luminances between light and dark areas of a scene than normal digital imaging techniques. The intention of HDRI is to accurately represent the wide range of intensity levels found in real scenes ranging from direct sunlight to shadows. Was originally developed in the 1930s and 1940s by Charles Wyckoff. Wyckoff’s detailed pictures of nuclear explosions that appeared on the cover of Life magazine in the mid 1940s.
This method was developed to produce a high dynamic range image from a set of photographs taken with a range of exposures. With the rising popularity of digital cameras and easy-to-use desktop software, the term HDR is now popularly used to refer to this process. The intention is to accurately represent the wide range of intensity levels found in real scenes, ranging from direct sunlight to the deepest shadows. This is usually achieved by modifying photos with image processing software for tone-mapping.
Infrared
In infrared photography, the film or image sensor used is sensitive to infrared light. Usually an “infrared filter” is used; this lets infrared (IR) light pass through to the camera, but blocks all or most of the visible light spectrum (the filter thus looks black or deep red).
When these filters are used together with infrared-sensitive film or sensors, very interesting “in-camera effects” can be obtained; false-color or black-and-white images with a dreamlike or sometimes lurid appearance known as the “Wood Effect,” an effect mainly caused by foliage (such as tree leaves and grass) strongly reflecting in the same way visible light is reflected from snow. The effect is named after the infrared photography pioneer Robert W. Wood, and not after the material wood, which does not glow under infrared.
One method of digital SLR infrared photography is to remove the infrared blocker in front of the CCD and replace it with a filter that removes visible light. Some cameras are more sensitive to infrared light and you can use a removable filter that can be attached to the lens.
