Perspective is just another way of saying “viewpoint”, it comes from the Latin root meaning "look through" or "perceive," and I assumed, perhaps wrongly, that everyone understands it.
We all know that certain lens aberrations can and do distort images, perhaps giving the false impression that the focal length of the lens can be a factor, and I did try to cover that misconception by saying that “Wide-angle lenses, and particularly extreme wide-angle lenses such as fisheye lenses, can produce considerable visible distortion. There are different types of optical distortion, including barrel and pincushion distortion. Fisheye lenses deliberately employ a different projection from conventional rectilinear lenses, producing the characteristic curved appearance of straight lines that do not pass through the centre of the image.
These effects can alter the appearance of objects, we can look at an image with obvious distortion and say “That was taken with a fisheye lens” but we can’t reach that opinion based on perspective.
A conventional rectilinear wide-angle lens, provided it is optically corrected, will reproduce the same geometrical perspective as a longer lens used from exactly the same viewpoint. The difference is the amount of the scene included in the photograph.”
Now, in photography, which is an odd mix of art and soft science, we tend to be very tolerant of people who misunderstand very basic terminology, as long as we understand what they mean. For example, plenty of people write F8 when they mean f/8, they are clearly referring to the f/number, even though they are saying that the lens used has a focal length of 8mm, and we let it go because we understand what they mean. But “perspective” is a common use word that we should all understand and if I failed to explain its meaning properly then I apologise.
I was just trying to write a simple article that everyone can understand, and I wrote it because, as we all know, lots of people still get it wrong, as demonstrated in some replies. As I alluded, the other reason for writing it is that I have some health issues at the moment, I’m very limited in what I can do and will be for some time, and one of the things that I can’t do is to get out and about to take photos, so, partly to keep myself occupied and partly because one of the few things that I can still do is to write.
