I always try to become a student of whatever I am doing. I ran across some information recently regarding
the relative size of digital camera sensors and film camera negatives. These
areas are directly proportional to how much information they can hold and relay
to a picture (print or viewing screen).
The above graphic was borrowed from a Wikipedia article
about “Image Sensor Formats” and I thought it portrayed the information very
effectively. It is not to scale but is proportionately correct.
The large “outer frame” represents a medium format camera
sensor (Kodak KAF 39000) and is also roughly comparable to medium format film
cameras although the 6x7 format would be a little larger.
The next frame shows the size of a 35mm negative and what is
called “full frame” sensors used in high end professional DSLR’s.
Then there is the APS-H (Canon) sensor used in some high end
(but not full framed) Canon DSLR’s. The
next two, the APS-C sensors, represent the vast majority of the DSLR’s commonly
used today.
The smaller frames, including the Four Thirds System
developed by Olympus and Panasonic are used by various compact and point &
shoot cameras.
As you can see from the sizes of the negatives and sensors
all of them must be enlarged to produce an image that you can see clearly and
use. It is a basic principle of photography that the more you enlarge an image
the more the image degrades. It has been long thought that the largest
practical enlargement for a 35mm negative or corresponding digital sensor is about
8” x 10.” That is why professionals use
medium format or even larger format films and digital sensors to produce the
best possible images for enlargement.
Since medium format and larger film & sensors are
typically used only by professionals we will ignore them for our purposes here.
It seems clear that the 35mm negative size and the corresponding “full frame”
digital sensors, as the largest generally available to amateur photographers
would result in the highest quality images, all other things being equal. Of
course, when comparing film to digital images one must also consider the
capacity of the sensor as well as the size.
Many “experts” seem to suggest that it takes a full frame
digital sensor with about a 25 megapixel capacity to equal the information
capacity of a 35mm negative. The fact that only high end professional digital
cameras costing thousands of dollars have this capability indicates that the
humble 35mm film camera of yesteryear (with a good lens of course) is still a
viable alternative for taking great pictures.
Of course, as the digital sensor technology improves it will
eventually surpass 35mm capability and get cheaper and cheaper while film and
film processing labs will become fewer and more expensive. In fact Nikon just today
announced their new D-800 full frame DSLR with 36.3 megapixel CMOS sensor. With
those kind of continuing advances it won’t be too much longer before film
photography becomes an increasingly rare and eclectic hobby shared only by a dedicated
few.
But for now at least I will keep taking pictures with my
film cameras.