It's a little apple & oranges as I understand it. The term 'pixel' is
shorthand for 'picture element' and refers to the number of elements
contained in the whichever device we happen to be referring to and not to
the physical size of those elements. Pixels are atomic; that is there's no
way for a device to record the top of a pixel as distinguished from any
other 'parts' of the pixel. Pixels are all or nothing affairs. Physical size
comes into play when we consider the size of the ccd, and the size &
resolving power of our monitors & printers. A printer that outputs a pixel
as a .1 inch dot (10 dpi) would obviously be useless (10 dots per inch would
be seen as a bunch of dots), whereas exceeding 260-300 dpi is wasted as well
since the unaided eye can't see any more anyway. As such, we have to be
concerned with the number of pixels on the ccd (an input device) *and* the
number of pixels on our monitors and printers (output devices). We must keep
in mind that the output device here, is the rectangle of output that appears
on our screens; it's the print not the printer. An 11x14" print requires
more pixels than a 5x7" print. Other considerations stem from these facts;
for instance, we gain nothing if we record more pixels than our output
device can use (depends on output size and printer quality etc...).
HTH.
-Lew
----- Original Message -----
From: "SteveS" <sgshiya@xxxxxxxxxxxx>
To: "List for Photo/Imaging Educators - Professionals - Students"
<photoforum@xxxxxxxxxxxxxxxxxxxxxx>
Sent: Wednesday, March 15, 2006 1:16 PM
Subject: Re: Question
----- Original Message -----
From: "Marilyn" <marilyn@xxxxxxxxxxx>
Subject: Question
Someone was asking me if the number of megapixels a camera has in some
way correlates to a photographer using a larger sheet of film - in other
words (I don't understand that question the way it is worded, myself) -
is using a 16 megapixel digital camera equal in photographic quality to a
photographer using a large format film camera loaded with sheets of 16X20
film?
I answered "yes," - more megapixels, more information recorded=better
quality. Likewise, more film surface, more information recorded=better
quality. How would some of you have answered?
Marilyn
Ain't necessarily so. Clairty is ranged by an actual formula and
principle in physics defined by the circled of illumination or 'circle of
confusion.' This has to do with the light passing through a lens to strike
a film plane or chip sensor.
The question is a good one, and I'd like to know the answer, but before
pixels can be recorded, the light muse register clearly on a plane of
focus. My understanding created by my photo finishing person has lead me
to understand that the scan size or file before printing makes for the
clarity of an electronic print. (I hate using the term digital.)
S. Shapiro
