http://www.arizonahighways.com/page.cfm?name=Photo_AskPhotogor search "aspect ratio" if this link becomes dated.
I always rolled my eyes whenever anyone mentioned their "no digital submissions" policy. But the fact that they don't know what "aspect ratio" means is incredible.
In any event the content of the above link is copied as follows (just in case they're embarrassed into deleting it):
"Do different types of camera formats confuse you? Do you wonder which type of 35 mm film you should use or how digital photography is changing the medium? If so, this is the place for you!
"Ask the Photo Editor" is an open forum for the discussion of photography-related issues. Each month Arizona Highways' photography editors will respond to some of the most frequently asked and pertinent photography questions that we receive. General photography questions as well as specific questions relating to photography in Arizona Highways magazine, calendars and books are welcome.
I recently received an email from reader Ben Bangerter regarding my use of the term “aspect ratio” in a recent “Ask the Photo Editor” column. I used the phrase to describe the cropping that occurs in the image capture area of many digital cameras when compared to the size of a 35mm frame of film.
I’ll be the first to admit that I’m not the most technical of photographers, and do appreciate the explanation, but among my professional colleagues, almost everyone I talk to uses “aspect ratio” to describe this function. I can easily imagine we’re all wrong, but I wonder if any of our other readers would care to add to the discussion or help further clarify the description?
— Richard Maack
Arizona Highways Photography Editor
Here’s Mr. Bangarter’s letter:
Richard,
This is not a question, but rather a couple of comments on your response to S. Mathia re: "Lens Choices for Canon 20D." I find it odd that you refer to the 1.6 cropping factor of the sensor in the 20D relative to a full 35mm frame as an "aspect ratio." The term aspect ratio is nearly universally used to describe the ratio of width to height of an image, which for the Canon 20D sensor is 3:2, the same as a 35mm frame. Describing the 1.6 cropping factor as a focal length multiplier is also misleading. It is correct to say that the angle of view of a 50mm lens on the 20D is the same as that of an 80mm lens on a 35mm film camera, but the focal length is a constant; a 50mm lens is exactly that, on the 20D, or a 35mm film camera, or an 8"x10" view camera. Of course, the field of view varies with the sensor size, and for purposes of calculation of depth of field, an appropriate choice of the circle-of-confusion diameter must be made, i.e., if a .030mm COF is appropriate for a 35mm frame, .019mm would be appropriate for the 20D sensor, for identical final print sizes without cropping. I mention these points because they seem to be the source of much confusion among photographers new to the digital SLR world (many discussions of these matters on photo.net forums, for example). And I believe some of this confusion arises from inexact explanations by those who know better!
From the foregoing, you probably consider me a tedious nit-picking jerk. Well... so be it. I greatly enjoy your magazine, particularly the photography, and find your columns interesting and (mostly) informative!
Yours for clarity and precision of expression,
Ben Bangerter "
