Re: Rotation & aspect ratio

k. harvey wrote:
On Sun, 12 Aug 2007 10:24:25 +0100, "Jeff Layman"
<jmlayman@xxxxxxxxxxxxxxxx> wrote:

Could someone please explain why, when I rotate a picture 90°
degrees in a viewing/editing program, the picture is stretched so
that long faces appear rounder? The actual change (as measured with
a ruler on the monitor screen) is from 1:1.25 in normal view to
1:1.43 in rotated view.

This happens with pictures from Kodak, Pentax, and Ricoh digital
cameras, when opened and rotated in Irfanview, Kodak, Adobe
Elements, or The Gimp .

It means that your monitor is not correctly adjusted for a 1:1 aspect
ratio. Just because you can select various desktop resolutions for
display doesn't mean that they are all supposed to be stretched to
the very edges of your monitor.

To correct for this use any editing program and use the vector
graphic tools to draw a perfect circle (or square). Make sure you use
a "lock aspect-ratio" function so that you are not drawing an ellipse
or rectangle when doing this. Then measure the vertical axis and the
horizontal axis of the object on your screen. Adjust the vertical and
horizontal height of your monitor display until the horizontal and
vertical distances of the circle or square are equal. Now your images
from all cameras in any software will display as they should no
matter how you rotate them.

Be prepared to see all your familiar faces in the photos as rounder
than you have been seeing them. The new and correct aspect ratio will
be halfway between what you have been seeing before and after
rotating.

Many thanks for this explanation and simple correction! OK, I lose a little
of the screen top & bottom, but at least the images are identical when
rotated.

Out of interest, do different printers suffer from this effect, too?

--
Jeff
(cut "thetape" to reply)


.

Relevant Pages

  • Re: Rotate image without perspective change?
    ... You rotate the print by ... You can do the same thing if you have a monitor with a pivot. ... the monitor, not the picture. ... The settings buttons on the front, have toggles for centring the screen ...
    (microsoft.public.windowsxp.photos)
  • Re: Rotate image without perspective change?
    ... You rotate the print by ... You can do the same thing if you have a monitor with a pivot. ... the monitor, not the picture. ... here) and check your desktop settings are correct... ...
    (microsoft.public.windowsxp.photos)
  • Re: Rotate image without perspective change?
    ... You cannot set your monitor for the x and y scales to be the same. ... You rotate the print by ... the monitor, not the picture. ...
    (microsoft.public.windowsxp.photos)
  • Re: Rotate image without perspective change?
    ... You rotate the print by ... You can do the same thing if you have a monitor with a pivot. ... the monitor, not the picture. ... here) and check your desktop settings are correct... ...
    (microsoft.public.windowsxp.photos)
  • Rotation & aspect ratio
    ... when I rotate a picture 90° ... the picture is stretched so that long faces appear ... This happens with pictures from Kodak, Pentax, and Ricoh digital cameras, ...
    (rec.photo.digital)