perspective w/ 35mm lenses?

The point you are missing I think is that wide angle and telephoto pictures
may have a specific look to them, but this is not due to perspective.

Try this exercise:
Take a wide angle shot in a room with the lens aimed into a corner of the
room (i.e. where the ceiling and walls come together). Without changing
where you are standing take the same shot with a telephoto lens. Print both
shots and measure the angles made by the lines where the ceiling and walls
meet. They will be the same.

Nest, re-shoot the same picture with either (choose one or the other and
leave it on for both shots)lens. First from x feet away and the second from
2x feet away. Print them and measure the angles again. They will have
changed because the perspective has changed.

A synonym for perspective might be "point of view".

If you would take the word of Ansel Adams, whom I believe understood
perspective quite well, I will post the operative paragraph and his example
under the header AA Perspective.

Hope this helps,
Dave

"Nostrobino" wrote in message
m...

"Jim Townsend" wrote in message
...
Nostrobino wrote:


You are saying that you really cannot see any difference in
perspective
between a shot taken with a 24mm lens and one taken with a 200mm lens?
Remarkable.

Both lenses see the same thing. The 200mm lens just sees less.

That's self-contradictory, Jim. If the 200mm lens "just sees less," then
it
does not "see the same thing."



Look at it this way.. If you fix a camera on a tripod, then take
a shot with a 24mm lens then another with a 200mm lens, the
24mm lens photo will have a wider field of view.

Note that magnification is nothing more than narrowing field of
view.

Right. So far, so good.


Perspective doesn't change.

Sure it does.



The 200mm lens will see less, but nontheless, it sees the *same*
thing the 24mm lens saw. The perspective is exactly the same.

No, it is not. The perspective in the PART of the 24mm shot that
corresponds
to the full 200mm shot DOES have exactly the same perspective. But there
is
a lot more to the 24mm shot than that, which you are ignoring. And it's
the
additional parts which give it a different perspective.


If you crop an area of the 24mm photo that corresponds to
what you see in the 200mm photo, then enlarge them to the same
size.. They will be exactly the same. This includes the apparent
'space compression'. There's no difference.

Correct. By so cropping it, you have radically changed the perspective.



You can create the effect of a longer lens by cropping. This is
what is happening with the digital zoom offered by consumer digicams.
The only thing that will be different is the depth of field.

As a matter of fact, with 35mm lenses, the term magnification
(as it relates to telescopes and binoculars) is rarely used.
It doesn't show up in manufacturers specs.. All they detail is
the field of view in degrees.

Try this.. Look across the room at an object with one eye
closed. Now take a long roll (like you get with wrapping
paper). Look at the object through the long roll. Doing
this narrows your field of view. Did the perspective change ?

You bet.

Look at it this way:

You will agree with me, will you not, that perspective is a characteristic
of any picture (photo or otherwise) which represents solid objects at
various distances?

Is there ANY part of such a picture (excepting blank spaces of course)
which
DOES NOT contribute to its perspective?

No. There is not.

Ergo, once you start cropping the wide-angle shot to make it look like the
long-lens shot, you are throwing out elements which were an important part
of the original perspective.

Any thing "X" from which you remove a substantial part is no longer X.
Logically, this applies to perspective just as much as it does to anything
else. The perspective of any picture is made up of various
elements--vanishing points, parallel lines converging into the distance,
etc. Start throwing out those elements around the edges (as by cropping)
and
you are ipso facto changing the perspective.

Again: shots taken with wide-angle lenses DO have a "wide-angle lens
look,"
or wide-angle perspective, anyone can see that they do, and no amount of
denial based on specious reasoning (no matter how often published) can
change this.

Take a shot of someone's dining room with a 17mm lens and they will be
impressed by "how much larger it looks!" Wide-angle perspective has
exaggerated the distances. Take a shot of oncoming highway traffic with a
300mm lens and the impression will be "how jammed together all the cars
are!" Telephoto perspective has produced spatial compression. You may deny
these effects all you like, go on insisting that "there is no wide-angle
look or telephoto look," but anyone with eyes can see that they are what
they are.

"Jeremy Nixon" wrote in message
...
Nostrobino wrote:

But why on earth would I want to do that? The purpose of a wide-angle
lens
is to deliver wide-angle images.

The reason to do it is to demonstrate that the perspective is the same
regardless of focal length.

But it DOESN'T demonstrate that.

Taking a shot with a 24mm lens and then cropping out everything except that
which would appear in a shot with a 200mm lens doesn't do anything but
EMULATE a 200mm lens. Obviously the perspective of the MODIFIED shot will be
identical to that taken with a 200mm lens in the example given.

ONCE AGAIN, that has never been in dispute here. Never.


In this particular example the camera position HAD to change in order to
fill the frame with the house with each lens. The difference in "look"
or
perspective however has nothing to do with camera position, it has to do
with focal length.

The "look" you speak of has to do with focal length.

Precisely. Earlier you claimed (like others here) that "there is no such
thing as a 'telephoto look'." (Your post of 8/2/2004 1:24 AM) If you are no
at last able to accept the evidence of your own eyes and agree that there is
indeed such a thing as a "telephoto look" (and of course a "wide-angle look"
too), then we are making progress.


The perspective, which
is independent of that "look",

The perspective has EVERYTHING to do with the "look." What do you think
perspective is?


has to do with camera position. You are
confusing the two things.

Perspective depends on three things: camera (or viewer) position, included
angle of view (or focal length), and the direction the camera (or viewer's
gaze) is pointed. This last has not even been mentioned here, but is just as
important as the others. This too can easily be proven by experiment, and a
more valid one than that "cropping out everything but the center of a
wide-angle shot" nonsense. Want to give it a try?

"Jeremy Nixon" wrote in message
...
Nostrobino wrote:

But why on earth would I want to do that? The purpose of a wide-angle
lens
is to deliver wide-angle images.

The reason to do it is to demonstrate that the perspective is the same
regardless of focal length.

But it DOESN'T demonstrate that.

Taking a shot with a 24mm lens and then cropping out everything except that
which would appear in a shot with a 200mm lens doesn't do anything but
EMULATE a 200mm lens. Obviously the perspective of the MODIFIED shot will be
identical to that taken with a 200mm lens in the example given.

ONCE AGAIN, that has never been in dispute here. Never.


In this particular example the camera position HAD to change in order to
fill the frame with the house with each lens. The difference in "look"
or
perspective however has nothing to do with camera position, it has to do
with focal length.

The "look" you speak of has to do with focal length.

Precisely. Earlier you claimed (like others here) that "there is no such
thing as a 'telephoto look'." (Your post of 8/2/2004 1:24 AM) If you are no
at last able to accept the evidence of your own eyes and agree that there is
indeed such a thing as a "telephoto look" (and of course a "wide-angle look"
too), then we are making progress.


The perspective, which
is independent of that "look",

The perspective has EVERYTHING to do with the "look." What do you think
perspective is?


has to do with camera position. You are
confusing the two things.

Perspective depends on three things: camera (or viewer) position, included
angle of view (or focal length), and the direction the camera (or viewer's
gaze) is pointed. This last has not even been mentioned here, but is just as
important as the others. This too can easily be proven by experiment, and a
more valid one than that "cropping out everything but the center of a
wide-angle shot" nonsense. Want to give it a try?

"nospam" wrote in message
...
In article , Nostrobino
wrote:

"nospam" wrote in message
...
In article ,
Nostrobino
wrote:

In the example I used before, if you take a photo of a house with a
24mm
lens from 24 feet away, and another photo of the same house with a
200mm
lens from 200 feet away, the house will be the same size on both
prints.
Yet
one photo will have a "wide-angle look" and the other will have a
"telephoto
look," despite the fact that you deny any such looks actually exist.

take both pics at 200 ft and crop the wide angle shot. they will look

But why on earth would I want to do that? The purpose of a wide-angle
lens
is to deliver wide-angle images.

to prove that camera *position* is what affects perspective, not focal
length.

As I just mentioned to Jeremy, . . . well here, I'll paste it in:

Perspective depends on three things: camera (or viewer) position, included
angle of view (or focal length), and the direction the camera (or viewer's
gaze) is pointed. This last has not even been mentioned here, but is just as
important as the others. This too can easily be proven by experiment, and a
more valid one than that "cropping out everything but the center of a
wide-angle shot" nonsense. Want to give it a try?


the same. yes, the house in the wide angle shot will be smaller -
magnify it so that it matches the other pic. it will be grainier or
more pixellated due to the magnification, but the distance compression
will be *the same* in both pictures because the camera did not move.

Of course. That has NEVER been in dispute. You are essentially repeating
what I said myself in my very first post on this subject. Again, who on
earth would actually do this, and for what reason?

to prove that camera *position* is what affects perspective, not focal
length.

Camera position, focal length, and direction the camera is pointing--these
are the things that determine perspective.


[ . . . ]

distances in the telephoto picture will look compressed and distances
in the wide angle pic will look stretced.

Exactly. One picture has a "telephoto look" (a telephoto perspective),
and
the other has a "wide-angle look" (a wide-angle perspective). That's
what
I've been saying all along. Now if you can just convince some of the
others
that there ARE such things as a "telephoto look" and a "wide-angle
look,"
that will be a great accomplishment, because two or three folks here
claim
they cannot see any such difference at all.

nobody denies the looks exist.

On the contrary, two ro three people here have denied EXACTLY that. Jeremy
just denied it yesterday, but now seems to have changed his mind, which is
encouraging.


however it is due to where the camera is
positioned relative to the subject, not the focal length of the lens.

Camera position, focal length, and direction the camera is pointing--these
are the things that determine perspective. But the "wide-angle look" or
"telephoto look" are NOT IN ANY WAY dependent on camera position.

Try this: Go out on any city street with your widest angle lens. Take lots
of pictures. Move around all you like, move forward and backward and
sideways, jump up in the air, climb a ladder, squat down on the sidewalk,
etc. while you're taking these pictures. Now do any of those shots NOT have
the "wide-angle look"? If as you say the "look" is dependent only on camera
position, then surely you should be able to find SOME position which does
not have the characteristic "wide-angle look." But (unless you just shoot
blank sky) you cannot.



that is because the camera
position changed.

In this particular example the camera position HAD to change in order to
fill the frame with the house with each lens. The difference in "look"
or
perspective however has nothing to do with camera position, it has to do
with focal length. If the camera were left in the same position for both
shots, then everything taken with the 24mm lens would look much smaller,
just as you say. However, the 24mm shot would STILL have a "wide-angle
look." Any time the 24mm lens is used and a print is made from the full
frame, that print will still have wide-angle perspective. This is not
dependent on camera position.

it has everything to do with camera position, and that can be verified
by the tests outlined previously.

Ready for the experiment that proves you wrong?

"nospam" wrote in message
...
In article , Nostrobino
wrote:

"nospam" wrote in message
...
In article ,
Nostrobino
wrote:

In the example I used before, if you take a photo of a house with a
24mm
lens from 24 feet away, and another photo of the same house with a
200mm
lens from 200 feet away, the house will be the same size on both
prints.
Yet
one photo will have a "wide-angle look" and the other will have a
"telephoto
look," despite the fact that you deny any such looks actually exist.

take both pics at 200 ft and crop the wide angle shot. they will look

But why on earth would I want to do that? The purpose of a wide-angle
lens
is to deliver wide-angle images.

to prove that camera *position* is what affects perspective, not focal
length.

As I just mentioned to Jeremy, . . . well here, I'll paste it in:

Perspective depends on three things: camera (or viewer) position, included
angle of view (or focal length), and the direction the camera (or viewer's
gaze) is pointed. This last has not even been mentioned here, but is just as
important as the others. This too can easily be proven by experiment, and a
more valid one than that "cropping out everything but the center of a
wide-angle shot" nonsense. Want to give it a try?


the same. yes, the house in the wide angle shot will be smaller -
magnify it so that it matches the other pic. it will be grainier or
more pixellated due to the magnification, but the distance compression
will be *the same* in both pictures because the camera did not move.

Of course. That has NEVER been in dispute. You are essentially repeating
what I said myself in my very first post on this subject. Again, who on
earth would actually do this, and for what reason?

to prove that camera *position* is what affects perspective, not focal
length.

Camera position, focal length, and direction the camera is pointing--these
are the things that determine perspective.


[ . . . ]

distances in the telephoto picture will look compressed and distances
in the wide angle pic will look stretced.

Exactly. One picture has a "telephoto look" (a telephoto perspective),
and
the other has a "wide-angle look" (a wide-angle perspective). That's
what
I've been saying all along. Now if you can just convince some of the
others
that there ARE such things as a "telephoto look" and a "wide-angle
look,"
that will be a great accomplishment, because two or three folks here
claim
they cannot see any such difference at all.

nobody denies the looks exist.

On the contrary, two ro three people here have denied EXACTLY that. Jeremy
just denied it yesterday, but now seems to have changed his mind, which is
encouraging.


however it is due to where the camera is
positioned relative to the subject, not the focal length of the lens.

Camera position, focal length, and direction the camera is pointing--these
are the things that determine perspective. But the "wide-angle look" or
"telephoto look" are NOT IN ANY WAY dependent on camera position.

Try this: Go out on any city street with your widest angle lens. Take lots
of pictures. Move around all you like, move forward and backward and
sideways, jump up in the air, climb a ladder, squat down on the sidewalk,
etc. while you're taking these pictures. Now do any of those shots NOT have
the "wide-angle look"? If as you say the "look" is dependent only on camera
position, then surely you should be able to find SOME position which does
not have the characteristic "wide-angle look." But (unless you just shoot
blank sky) you cannot.



that is because the camera
position changed.

In this particular example the camera position HAD to change in order to
fill the frame with the house with each lens. The difference in "look"
or
perspective however has nothing to do with camera position, it has to do
with focal length. If the camera were left in the same position for both
shots, then everything taken with the 24mm lens would look much smaller,
just as you say. However, the 24mm shot would STILL have a "wide-angle
look." Any time the 24mm lens is used and a print is made from the full
frame, that print will still have wide-angle perspective. This is not
dependent on camera position.

it has everything to do with camera position, and that can be verified
by the tests outlined previously.

Ready for the experiment that proves you wrong?

"nospam" wrote in message
...
In article , Nostrobino
wrote:

Certainly not, because perspective is a function of the picture
in
its
entirety. When you crop out parts of the picture as you
describe,
you
change
its perspective.

so if i take a print and then crop away parts of it by cutting it
with
scissors, i am changing the perspective of the remaining parts of
the
picture?

Exactly.

ok, how does the inner portion of a picture change by cutting the
outer
portion off?

It doesn't. Why would it?

first you said if i crop away parts of it with scissors, that changes
the perspective, now you say it doesn't. both cannot be true.

Read it again. I said the center portion doesn't change either way.

Once you remove everything but the center portion of the picture, you have
changed the perspective. HOW you do this doesn't matter.



or better yet, what if i just put my hands over the outer
portion, blocking it from view. same net effect, but no paper cutting,
and the ability to 'undo' it at any time.

Sure. Same thing.

same thing as what? does it change perspective or not? if so, how?

Once you remove everything but the center portion of the picture, you have
changed the perspective. HOW you do this doesn't matter.



However, telephoto lenses are useful anyway since they allow you to
get
telephoto perspective without having to cut away most of that paper
that
you
paid for, which is not only a waste of materials but also tends to
result in
rather tiny final prints. But you knew that anyway, right?

i know that paper, even a fair amount of it, weighs less and certainly
costs substantially less than a bulky heavy telephoto lens. infact, it
can replace several different telephoto lenses. therefore, i don't
really mind a little waste. its even less fragile too. all in all, a
win-win. the only glitch i see is that it is easier to bring a
telephoto lens thru airport security than it is to bring scissors.

Absolutely. My eight-year-old great-niece had her little toy scissors
confiscated before they'd let her on the plane. They would just barely
cut
paper, but they had to be taken.

no they did not have to be taken.

http://www.tsa.gov/public/interweb/a..._Prohibited_12
_18_2003.pdf

plastic or metal scissors with blunt tips are acceptable for carry on;
scissors with pointy ends are prohibited. presumably, your niece's
'litte toy scissors' have blunt rounded ends like most children's
scissors. if so, they were improperly confiscated.

Lots and lots of things are improperly confiscated. Passengers have had
JEWELRY confiscated because some dumbass insisted it was dangerous. Ann
Coulter had a piece of gold jewelry confiscated because it looked like a
small cartridge. And it was "lost"--she never got it back.



of course, what the tsa does is often entirely different from what they
are supposed to do, but that is a topic for a different newsgroup.

Exactly so.



maybe i'll keep a telephoto lens just for air travel.

I would keep the telephoto lens anyway. It's an all-around more
satisfactory
tool for producing telephoto shots than a scissors is.

the telephoto lens costs more money than paper and i'm cheap.
unfortunately i bought the lens before you gave me this excellent
advice. at least i can avoid getting additional long lenses in the
future.

I never advised you to refrain from buying lenses, and I do not do so now. I
think you should buy all the lenses you like. I do! Lenses are good for you.


furthermore, a package of paper lets me pack lighter; i will
just need to buy scissors after the flight. that should be easier than
finding the right lens in the right camera mount in some foreign city.

Lenses are better than paper and scissors. More expensive and heavier as you
say, but better.

"nospam" wrote in message
...
In article , Nostrobino
wrote:

Certainly not, because perspective is a function of the picture
in
its
entirety. When you crop out parts of the picture as you
describe,
you
change
its perspective.

so if i take a print and then crop away parts of it by cutting it
with
scissors, i am changing the perspective of the remaining parts of
the
picture?

Exactly.

ok, how does the inner portion of a picture change by cutting the
outer
portion off?

It doesn't. Why would it?

first you said if i crop away parts of it with scissors, that changes
the perspective, now you say it doesn't. both cannot be true.

Read it again. I said the center portion doesn't change either way.

Once you remove everything but the center portion of the picture, you have
changed the perspective. HOW you do this doesn't matter.



or better yet, what if i just put my hands over the outer
portion, blocking it from view. same net effect, but no paper cutting,
and the ability to 'undo' it at any time.

Sure. Same thing.

same thing as what? does it change perspective or not? if so, how?

Once you remove everything but the center portion of the picture, you have
changed the perspective. HOW you do this doesn't matter.



However, telephoto lenses are useful anyway since they allow you to
get
telephoto perspective without having to cut away most of that paper
that
you
paid for, which is not only a waste of materials but also tends to
result in
rather tiny final prints. But you knew that anyway, right?

i know that paper, even a fair amount of it, weighs less and certainly
costs substantially less than a bulky heavy telephoto lens. infact, it
can replace several different telephoto lenses. therefore, i don't
really mind a little waste. its even less fragile too. all in all, a
win-win. the only glitch i see is that it is easier to bring a
telephoto lens thru airport security than it is to bring scissors.

Absolutely. My eight-year-old great-niece had her little toy scissors
confiscated before they'd let her on the plane. They would just barely
cut
paper, but they had to be taken.

no they did not have to be taken.

http://www.tsa.gov/public/interweb/a..._Prohibited_12
_18_2003.pdf

plastic or metal scissors with blunt tips are acceptable for carry on;
scissors with pointy ends are prohibited. presumably, your niece's
'litte toy scissors' have blunt rounded ends like most children's
scissors. if so, they were improperly confiscated.

Lots and lots of things are improperly confiscated. Passengers have had
JEWELRY confiscated because some dumbass insisted it was dangerous. Ann
Coulter had a piece of gold jewelry confiscated because it looked like a
small cartridge. And it was "lost"--she never got it back.



of course, what the tsa does is often entirely different from what they
are supposed to do, but that is a topic for a different newsgroup.

Exactly so.



maybe i'll keep a telephoto lens just for air travel.

I would keep the telephoto lens anyway. It's an all-around more
satisfactory
tool for producing telephoto shots than a scissors is.

the telephoto lens costs more money than paper and i'm cheap.
unfortunately i bought the lens before you gave me this excellent
advice. at least i can avoid getting additional long lenses in the
future.

I never advised you to refrain from buying lenses, and I do not do so now. I
think you should buy all the lenses you like. I do! Lenses are good for you.


furthermore, a package of paper lets me pack lighter; i will
just need to buy scissors after the flight. that should be easier than
finding the right lens in the right camera mount in some foreign city.

Lenses are better than paper and scissors. More expensive and heavier as you
say, but better.

"Jeremy Nixon" wrote in message
...
Nostrobino wrote:

As I have said befo you can magnify a wide-angle shot to your heart's
content and it will still be a wide-angle shot, still have the
"wide-angle
look" and wide-angle perspective. Print it postage-stamp size or super
mural-size, it still will have the "wide-angle look." You cannot change
that
without modifying the picture itself.

If the "telephoto look" is a product of lens focal length, then why does a
50mm lens on a (Nikon) digital SLR give the same "look" as a 75mm lens on
a 35mm camera? Should not the 50mm lens on the digital give the same
"look"
as a 50mm lens on 35mm?

You implicitly agree, then, that there is a "look" related to focal length,
at least on any given camera.

On a given camera (or rather a given format), focal length determines field
of view. On a full-frame 35mm camera, a 50mm lens covers about 47 degrees
corner to corner on the negative. On a half-frame 35 the same 50mm lens
would cover a smaller field of view, roughly equivalent to that of a 72mm
lens on a full-frame 35.

It (or any other lens) covers a smaller field of view on a digital SLR for
the same reason: the digicam's sensor is substantially smaller than the
24x36mm frame of a 35. Any 35mm SLR lens is effectively "longer" on a dSLR
unless its sensor is also 24x36mm.

Contrariwise, on a 6x6cm SLR a 50mm lens would be an extreme wide angle
because the format is much larger.

"Jeremy Nixon" wrote in message
...
Nostrobino wrote:

As I have said befo you can magnify a wide-angle shot to your heart's
content and it will still be a wide-angle shot, still have the
"wide-angle
look" and wide-angle perspective. Print it postage-stamp size or super
mural-size, it still will have the "wide-angle look." You cannot change
that
without modifying the picture itself.

If the "telephoto look" is a product of lens focal length, then why does a
50mm lens on a (Nikon) digital SLR give the same "look" as a 75mm lens on
a 35mm camera? Should not the 50mm lens on the digital give the same
"look"
as a 50mm lens on 35mm?

You implicitly agree, then, that there is a "look" related to focal length,
at least on any given camera.

On a given camera (or rather a given format), focal length determines field
of view. On a full-frame 35mm camera, a 50mm lens covers about 47 degrees
corner to corner on the negative. On a half-frame 35 the same 50mm lens
would cover a smaller field of view, roughly equivalent to that of a 72mm
lens on a full-frame 35.

It (or any other lens) covers a smaller field of view on a digital SLR for
the same reason: the digicam's sensor is substantially smaller than the
24x36mm frame of a 35. Any 35mm SLR lens is effectively "longer" on a dSLR
unless its sensor is also 24x36mm.

Contrariwise, on a 6x6cm SLR a 50mm lens would be an extreme wide angle
because the format is much larger.

"Nostrobino" wrote in message m...


You are not answering my earlier argument. The perspective of any picture
(photo or otherwise) is made up of several elements--vanishing points,
parallel lines converging into the distance, and so on.


The only thing that can change the position of vanishing points is to
change your point of view, i.e., your location, or to point the camera
in a different direction. Bear in mind that if I crop a picture the
vanishing points do not change. How could they? If I take a
photograph then you would agree that the resulting perspective can be
defined by a set of vanishing points, right? If I then crop the
image, what exactly is it that makes the vanishing points move?


If you don't understand this, you ought to get a book on the basics of
perspective before we proceed further. Any good library that has books on
drawing, etc., should have something that covers this subject.

Good advice. Follow it.

Brian
www.caldwellphotographic.com