Absolute Beginner's Guide to Digital Photography

(Ann) #1
Resolution of Film: How Many Pixels?
The first high-end consumer cameras in 1998 were 1-megapixel or less, and could
create digital images up to 1280×960 resolution. Since 1998, the digital camera
industry has continually released better cameras. Cameras producing images of
3000 ×2000 pixels are now under the $1,000 mark. To the untrained eye, images
from these advanced third-generation cameras are the same as a regular film
image.
If today’s cameras are thatgood, have they finally caught up with traditional film in
terms of resolution? Essentially, no. The resolution of film—negative and positive
(slide) film—is much, much higher. Film has a resolution of between 20 and 27 mil-
lion pixels!
Film is an analog medium and is affected greatly by the lens, film speed, type of
film, lighting conditions, handheld stability of the photographer, and scanner. A
compromise in quality in any of these areas will lower this resolution dramatically
to that of a 6-megapixel camera or less.
The most significant disadvantage to film is that it must be scanned. Digital images
are made up of ones and zeros that can be imported into your image editor with no
loss. Film must be scanned, and scanner quality varies dramatically, with drum
scanners being the best at capturing detail. As you increase the resolution of the
scanner however, you reach a threshold where further detail becomes noise.
The scanner then becomes the limiting factor in this film/digital comparison.
The scanner forces film to about a 20-million pixel limit. This means that a digital
camera that can produce images at 5000×4000 pixels will equal the quality of a
scanned negative. Today’s 11-megapixel cameras, which feature 4064×2704-pixel
resolution, are closing in. Digital film “backs” (extensions that fit onto the back of
the camera) for medium-format cameras already surpass this resolution, but are
incredibly expensive ($10,000 and up, minus the camera) and slow (shutter speeds
of one second or longer).
The pictures produced from disposable cameras equal the resolution of a 2- to 4-
megapixel camera because of their plastic lenses, fixed shutter speed, fast film, and
amateur hands (see Figure 12.1).
So, if anyone asks whether digital cameras are available that equal the quality of
film, the answer is yes...and no. The “yes” part means that cameras and lenses are
available that equal film-camera quality. The “no” part is that these tools rely on
the photographer.

178 ABSOLUTE BEGINNER’S GUIDE TODIGITAL PHOTOGRAPHY

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