Perspective Off Topic.

I have just been watching a TV Orchestra along with a solo piano. One of
the (video) camera shots showed an oblique view along the keyboard of the
pianist playing.

The key board looked wider at the far end that at the near end and very much
so. The image was not reversed and the background players looked all OK as
did all other views of the orchestra. There were no mirrors to be seen nor
was there any smoke.

How can this be with a fixed ( I assume) lens camera.

--
Otzi

This is an optical illusion caused by using a very long lens on the
camera. The perspective of a picture is due to the position of the
camera. In this case the camera was very far away. Because the image is
cropped it looks unaturel. Actually, the far end of the keyboard will
be slightly smaller than the near end but, becuse the difference is
much less than you expect, it looks like its wider. The only cure for
this in TV is to place the camera closer. In still photography a
tilting back could be used to distort the perspective to make give it
some diminishing perspective. This is the opposite of what is usually
done in photographing buildings etc.

--
Richard Knoppow

"otzi" wrote in message
...
[SNIP]

Doesn't the question of whether perspective is OT or not entirely depend
upon your point of view?

Sorry, couldn't resist! ;-)


Peter

"Richard Knoppow" wrote in message
oups.com...
This is an optical illusion caused by using a very long lens on the
camera. The perspective of a picture is due to the position of the
camera. In this case the camera was very far away. Because the image is
cropped it looks unaturel. Actually, the far end of the keyboard will
be slightly smaller than the near end but, becuse the difference is
much less than you expect, it looks like its wider. The only cure for
this in TV is to place the camera closer. In still photography a
tilting back could be used to distort the perspective to make give it
some diminishing perspective. This is the opposite of what is usually
done in photographing buildings etc.

--
Richard Knoppow



Thanks for that Richard. Some thought and one would have realized that long
tele views may give this effect. Viz. the shape of a car with a large tele
lens. Also as was pointed out, if an oblique view of a box if perfectly
corrected it can look bigger at the other end. Our minds are strange things
at times. mine any way. Just was thrown by the piano, choosing to ignore
that the camera was shooting from the back of the auditorium.
--
Otzi