Image Size and Resolution
When sizing an image for projection the only dimensions that matter are the width
and height in pixels. Many people feel the need set resolution at 72PPI or 96PPI but
Pixels Per Inch (or Centimetre) are only relevant when preparing an image to print.
A 1400 pixel x 1050 pixel image at 300 PPI will project identically to a 1400 pixel x
1050 pixel image at 72 PPI.
A 1024 pixel x 768 pixel image will fill the screen on a monitor or projector with the
same 1024 x 768 native resolution. Many clubs use such projectors.
The PAGB, and many clubs, use projectors with a native resolution of 1400 pixels x 1050
pixels. Provided that organisers ensure, (as they should for maximum quality) that
images are not resized by the projection software or device settings, smaller
images submitted, such as 1024 x 768, will occupy an area that size in the centre of
the larger screen, with the unused area automatically filled with black whilst an
image file larger than 1400 x 1050 will be uniformly cropped to fit the 1400 x 1050
area. Anything outside that area will not be displayed.
An alternative is to create an image that exactly fits the native resolution of the
projector. This allows the author to fill the empty space with their own choice of
colour and texture – to make it a part of the picture rather than surround it with the
default black. You can also create borders and choose where the image will
appear on the screen. Perhaps an off centre image looks better?
Learning to size and resize images is fundamental to Digital Imaging and could be
considered synonymous with mounting prints.