General FYI- For lack of a reference point, celestial objects appear flat (2D) to the eye. Most people assumed the earth and moon were flat for thousands, if not millions, of years.
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Oops sorry about that I shouldn't have mentioned anything about a specific entry. I'm not trying to influence voting just wanted to discuss DOF.
I disagree with the notion that 3 train cars close to the lens all in focus shows more DOF than an entire train farther away from the lens all in focus.
Here is a quick google search for the definition of DOF:
"Definitions of Depth of field on the Web:
The distance between the nearest and farthest points that appear in acceptably sharp focus in a photograph. Depth of field varies with lens aperture, focal length, and camera-to-subject distance.
www.shortcourses.com/choosing/glossary/19.htm
According to that depth of field is the distance between the nearest and farthes
in acceptably sharp focus in a photograph. Depth of field depends on the nearest and farthest points in a photograph. In the train example, the nearest and farthest points would be seperated by more distance in a whole train than 3 cars no matter the distance from the lens.
The fact that you can accomplish this with a larger aperture by increasing the distance from the lens does not take away from it's DOF.
Your definition is only for depth of field in general, not DEEP depth of field. In the latter case, you'd need something close and something far way- both in focus. For this challenge, some people confused deep depth of field with distance (they are not interchangeable). In the example of a train at 30 miles distance, everything is far way, so you could shoot that wide open and potentially still be in focus. On the other hand, an extreme macro shot that shows only a few inches of depth could represent deep DOF, though only those experience with macros might recognize that.
I disagree with the notion that 3 train cars close to the lens all in focus shows more DOF than an entire train farther away from the lens all in focus. ... In the train example, the nearest and farthest points would be seperated by more distance in a whole train than 3 cars no matter the distance from the lens.
Not necessarily so. If travelling in a direction perpendicular to the axis of the lens a train of any number of cars can appear to be all in focus in a very shallow DoF photo. And if shot from a small angle three train cars can be shown with a very deep depth of field even if they are fairly close to the lens.
Originally posted by scalvert:
... an extreme macro shot that shows only a few inches of depth could represent deep DOF, though only those experience with macros might recognize that.
Such a shot could be called deep DoF when compared to the usual shallow DoF found in most wide-aperture macros but it's difficult to think of a few inches as a deep depth of field. The details of the challenge currently being judged contrast deep DoF with shallow DoF but not necessarily with macros; and I expect such entries will suffer in the eyes of the voters.
