Originally posted by StiffLegged Sorry Swan, but changing the lens doesn’t change perspective: only changing your viewpoint will do that.
That's an old bar room bet cliche.
As soon as you do what you really do, and fill the frame by moving close with the shorter lens, which is what everyone does, you fill the frame and that is what the long lens changes the perspective is about. When you do it as everyone does it, changing your position to keep the subject the same in the frame it changes the perspective.
That comment is just semantics, in that people shorten the concept by leaving out the "keeping the subject the same size" part, which in use isn't necessarily stated but isn't stated, as it's assumed no one is silly enough to not alter their position when they change lenses, unless it's telephoto work and the subject is too far away with the shorter lens.
If you change lenses and move so the subject fills the same amount of the frame, the long lens will shrink the back ground allowing you to remove distracting elements from the frame. It's standard photographic practice, at least among trained photographer.
Quote: changing the lens doesn’t change perspective: only changing your viewpoint will do that.
Anyone trained in studio photography understands what is meant and it's good practical advice.
But stated as it is, it's only useful for winning bets in bars.
The reason for changing positions when you change lenses is so obvious, whoever coined this phrase did't think anyone would be silly enough to misinterpret it. But that being said, the proper way to state it would be "Keeping the subject the same size, using a longer lens compresses the background." If you didn't take short-cut with by using the first phrase instead of the second, there would have been no confusion. This was originally Tony Northrup click bait by the way. 10 years ago smart Alecs were all over it.
I remember my first response when hearing it "Using a longer lens doesn't change perspective." But it dramatically changes the size of the subject. People who float that particular bit of knowledge always leave that part out. Same perspective but not the same size. So still a hugely different image. And in truth the perspective is changed, in that the wider lens shows so much more of the background. It's a completely different image.
I write this particular sentiment off as akin to a parlour trick, with no useful application, in that's it's based on a common phrase that over simplifies the issue to the point of uselessness on the basis of a practice , framing up with a long lens and then maintaining one's position while switching to a smaller lens, that no one in their right mind would employ and therefore anticipate in their consideration of the statement. It's a disservice to those trying to understand the topic.
It actually took me a few days after someone first wasted my time with this concept to figure out why it was so wrong. Don't feel bad if you got hooked.