See also:   [Film Terms (on film page)]
                   [Film]
                   [the Close Up]
                   [Art Films]
                   [(art) Concepts]

Cropping

Basically the term derives from "cropping one's hair" - that is
some sort of a hair-cut or "cropping back" from "cutting back".

Any time part of an image is "cut off" from the final presentation
(usually at the sides or from the top or bottom) it is said to
have been cropped. Take out a pair of scisors and cut out a 
coupon from the newspaper and you are "cropping the newspaper page".

Cropping is used to remove "extra" portions of an image usually
with the purpose of making the image (at its present scale) fit
into a given space; eg, taking a poster and either folding under 
part of it or actually cutting part off it off to make it fit 
into a given picture frame that you want to use. 

or...

Take a wide-screen film and "crop" it to fit the older 3x4 format.

Thus, 9x16 --> 3x4 doesn't map arithmetically; 

      3x4 x 3 gives:  9 x 12 (thus 1/4 of the sides is cropped out)
      3x4 x 4 gives: 12 x 16 so  12  x  16
                                ----   ---- gives  0.75 x 1
                                 16     16

Note: The final format "should" be the most common for "leter box",
      but leaving only 1/8 of the top and bottom of the screen blank.
      This is ONLY used in the panaoramic (or wider; eg, 70mm+) film formats.

The most common form of cropping is simply to hack off one side or the 
other. In this case we simply lose a portion of the original image.
In film the "scanning crop" is used:  If two people are talking then
the film is cropped so that they are fully in screen or at very least
on the border of the screen - worst is the center cut which isn't often
used since the rest of the film to their right or left is BLANK.

Thus in films where two people are having a dialog, first one is "on screen"
and then the other - back and forth. For a brief time when film makers new
that their film would be cropped for television they purposely shot in a
restricted format using the sides with simply extraneous bits of scenery
or other B/G. 

Note that spliting an image so that it can be published in a book
is not *technically* cropping. The worst case is when a picture that
is wider than a page in a book is NOT split or cropped and is printed
onto the page and almost un-seeable in the middle. An alternative
is called "over-leafing" which makes a fold-out page that is larger
then the book's regular pages; eg, the "centrefold" in Playboy magazine
was innovative in this, giving rise to the term "centerfold girl" 
which was itself an evolution of the "pin-up girl" photo concept. 

In many cases, published pictures are printed so that there IS
a definite (and discardible) margin around the primary part of
the subject. Some web pages could learn from this. But, of
course this all goes back to LAYOUT in general. But, i digress.

Also, consider the "pop-up book" format as a variant as well.

Creative Uses of Cropping

Since the audience is modern and aware of cropping, some film makers
use that to interpose other images in between - thus almost "begging 
the question of cropping". Note the use of the "two people talking
on the phone" with the "split screen" - clearly cropped. And as a
"normal" film element the audience understands what is happening.

However, there is NO reason that the film can't be cropped in any
number of ways. This idea is behind the TILE-ING that we see in
many cases; the most notable was the use of tiling in the intro
to "The Brady Bunch" TV series. 

Technically tiling is NOT cropping - but, clearly any sort of
cut-ing and mixing of images suggests the idea of tiling and
cropping depending on how they are done. 

Also, the usual "line of demarcation" is almost always a single
line (either strictly horizontal or strictly vertical). There is
no reason that this can't be a jagged line (eg, suggesting a
"tear-ing" of the images and/or what is on them). In some cases
this is made apparent by an FX which uses a "torn paper edge"
- and roughly so - to suggest this.

Another form of cropping is the common "puzzle piece" cut along
the edges which are then fit together - often paralleling the
progress of the plot. 

Other FX's that parallel cropping are the "hole in the middle"
of the screen allowing an image to show thru. Again there is
much potential for this as a common "binding element" to tie
different parts of the story together. 

In the limit of course, over-laps of one image on top of the
other remove the idea of cropping and that aspect of "layering"
becomes dominant. The commonist version of such layering is
the fluttering down into view of photographs - usually showing
the progession of time - this theme is re-iterated by use of
the "scrap book / family album" to show this progress. And
in this case, the "flipping the pages of a book" - very 
common - is used as well. And the "page-edges" of the book
give the visual clue that we are seeing one page of several.
And of course the "page turn" or "page tear" transitions
are in this vein as well. An animated pair of scisors is
the most common added "action element" - ie, performing
the CROP itself "right before our eyes".


Chronology

film clip examples, etc.