Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Perspective does change with distance - that is a given but focal length affects perspective as well - I think you are tilting at windmills again - how is it that someone can agree with you and you still react defensively as if they are disagreeing with you? The introduction of focal length to the discussion just adds a little clarity, and contributes to a more thorough coverage of the concept. Extension and compression distortion are two types of perspective disruption - that is pretty clear. And perspective distortion is a component of perspective - which is a valid point in any discussion of perspective.

https://en.wikipedia.org/wiki/Perspective_distortion_(photography)

If you still think that lenses have nothing to do with how reality is perceived - perspective-wise - then I am pretty sure you need your perspective realigned, maybe even de-obfuscated. Really Floyd, this is Perspective 101 we're talking about here.

Do you not fully understand the first line in the link above?

"In photography and cinematography, perspective distortion is a warping or transformation of an object and its surrounding area that differs significantly from what the object would look like with a normal focal length, due to the relative scale of nearby and distant features. Perspective distortion is determined by the relative distances at which the image is captured and viewed, and is due to the angle of view of the image (as captured) being either wider or narrower than the angle of view at which the image is viewed, hence the apparent relative distances differing from what is expected. Related to this concept is axial magnification -- the perceived depth of objects at a given magnification."

That's pretty clear that both play a part in perspective - just from a different point of view. (can I say that?)

I think it's best you don't argue the obvious.

By way of example - can you tell me how you could get the image of the guy in this link with a tele lens? Of course distance is a factor - but so is focal length - in that you cannot effectively get this image with a long lens, no matter how hard you try. And in order to show that if you crop out a portion of the center of a wide angle shot at the same distance as a tele shot your perspective will be the same - but would have to be considerably further away where the three dimensionality of the subject is less of an issue. Why? because at close distances really wide angle lenses magnify things that are up close a lot more than things that are further away - aka - extension distortion - which affects perspective in a unique way. What you say isn't wrong, but it doesn't tell the whole story, mainly because you continue to struggle with the concept. Go out, take pictures, and support your argument, otherwise stop trying to confuse people with your partial and misleading answers. Trust me, if you admit to your mistake, or more accurately the fact that I did not make a mistake, the earth will continue to rotate and provide all of us with the illusion that the sun will rise in the morning. It's all a matter of perspective, isn't it.

Don't you ever tire of disagreeing with everyone?

http://www.vistaview360.com/photography/perspective-distortion.htm

© Copyright Vistaview360.com

Apaflo Loc: Anchorage, Alaska

That is correct and the voluminous text following it obfuscated the significance.

Your image posted shows the perspective that results purely from distance.

bkellyusa Loc: Nashville, TN

Gene,

I've got one question. What exactly is the "normal focal length?"

selmslie Loc: Fernandina Beach, FL, USA

The conventional definition is the focal length equal to the diagonal of the sensor or film format. For full frame 24x36 that would be about 43 mm. For APSC it would be about 28 mm (Nikon) or 27 mm (Canon).

But "normal" is really whatever you find most comfortable for your everyday view of the world. For me it is 35 mm for full frame.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

In common usage, it is the length of the diagonal of an image sensor (or film) -

ust like Scotty (selmslie) wrote it's loosely defined as the length of the diagonal.

https://en.wikipedia.org/wiki/Normal_lens

But it can vary from a little shorter to a little longer. Also the aspect is going to be different and yield a different number - a 6cmx6cm (medium format film camera, like a Hasselblad) will show a shorter diagonal than a Horseman 6cmx9cm, even though they both use the same film.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

First, it's not my image. See the copyright notice.

Second, take a similar portrait up close with a 14mm lens and then with a 200mm lens. Post the result. Make them look the same.

The only obfuscation is between your eyes and your brain. The articles I posted show and explain the relationship between perspective, distance to subject, and the part you can't get your head around, the focal length - and how they all interact to provide a "perspective."

Apaflo Loc: Anchorage, Alaska

Go ahead! Use a 200mm macro lens and you'll see the same effect.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

No Floyd, this one's on you.

selmslie Loc: Fernandina Beach, FL, USA

Sorry Floyd, there is more to perspective than just the distance to the subject.

You have to consider the shape of the subject, just as Gene illustrated, as well as the direction from which you are shooting. If you move the camera up, down, right or left you are also changing the perspective because you are changing the relationship of the subject to its surroundings as well as changing which aspect of the subject you are seeing. All of this changes even though you hold the distance to the subject constant.

When you change only the focal length you are also changing the proportion of the image that is occupied by the subject in relation to the surroundings. This means that, even if the distance to the subject is constant, the perspective changes.

Perspective is just not as simple as your limited definition of it.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Here is another example - we are a visually oriented group, photographers, that is, so visuals help, even those who by choice or circumstance can't or won't actually go out and take pictures to explore and support their theories.

https://petapixel.com/2012/08/12/how-focal-length-affects-your-subjects-weight-in-portraits/

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

You must be a card-carrying member of this organization:

http://www.alaska.net/~clund/e_djublonskopf/Flatearthsociety.htm

There is an Alaska chapter, btw.

Open your mind, and the obfuscation will be instantly removed.

Apaflo Loc: Anchorage, Alaska

Fact: perspective is the effect of distance, not focal length.

boberic Loc: Quiet Corner, Connecticut. Ex long Islander

The term "Normal" was first used to describe a lens viewing angle that was equal to the way the eye sees a scene. That's why many film cameras came with a 50 mm lens attached. So today 50 mm would be "normal" for a full frame and it's equivilent for a crop frame.

selmslie Loc: Fernandina Beach, FL, USA

The topic being discussed is about, "... Perspective and Apparent Depth of a Photo."

Apparently you can only understand a single aspect of perspective to the exclusion of all others. Too bad.

You seem to want to reduce every photographic concept to a simple, dogmatic statement. The limitation is in your own mind, not ours.

From your "perspective" everyone in the USA is south of Barrow and thereby geographically inferior. That does not mean that they are intellectually inferior.

Apaflo Loc: Anchorage, Alaska

Focal length does not change perspective! That single fact makes your entire "discussion" meaningless.