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perspective w/ 35mm lenses?

 
 
mcgyverjones
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      08-07-2004

"Nostrobino" <(E-Mail Removed)> wrote in message
news:uU7Rc.262$(E-Mail Removed).. .
snip
> There's a photographer who prefers very long
> lenses (e.g., 300mm on a 35) for shooting half-length pictures of

beautiful
> girls. He doesn't NEED a long focal length; the girls are models and will

be
> wherever he places them, but he likes the strong look that the spatial
> compression of a really long lens gives him.


This is exactly where you are wrong. The tele lens does not give any kind
of compression at all.
The apparent compression is purely a result of the camera position.
The lens simply allows the photographer to crop in camera without losing
resolution.
I can't believe we are still going on about this, it's photo 101.


 
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Nostrobino
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      08-08-2004

"mcgyverjones" <mcgyverjones(spamout)@hotmail.com> wrote in message
news:0idRc.46212$(E-Mail Removed) ...
>
> "Nostrobino" <(E-Mail Removed)> wrote in message
> news:uU7Rc.262$(E-Mail Removed).. .
> snip
> > There's a photographer who prefers very long
> > lenses (e.g., 300mm on a 35) for shooting half-length pictures of

> beautiful
> > girls. He doesn't NEED a long focal length; the girls are models and

will
> be
> > wherever he places them, but he likes the strong look that the spatial
> > compression of a really long lens gives him.

>
> This is exactly where you are wrong. The tele lens does not give any kind
> of compression at all.
> The apparent compression is purely a result of the camera position.
> The lens simply allows the photographer to crop in camera without losing
> resolution.


He isn't "cropping" anything, any more than using a normal f.l. lens is
"cropping" what WOULD have appeared in a wide-angle shot. He's using the
300mm lens because that is what gives him the perspective he wants. Does
this also imply a more distant camera position? Obviously!


 
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Nostrobino
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      08-08-2004
Dave, I've been making several attempts to reply to this since yesterday,
but for some reason my server keeps rejecting my posts. It's been doing this
occasionally lately, no idea why. Today I tried copying my yesterday's reply
into a fresh post, but it rejects that too. Yet I have no problem replying
to other posts. Curiouser and curiouser, as Alice said.


"Dave Martindale" <(E-Mail Removed)> wrote in message
news:cf13vr$hhd$(E-Mail Removed)...
> "Nostrobino" <(E-Mail Removed)> writes:
>
> >> Rather than go over all the issues, may I suggest you read the
> >> comprehensive entry in The Focal Encyclopedia of Photography under
> >> "Perspective". One pertinent quote on linear perspective* is:

>
> >> "Since short focal length wide angle lenses tend to be used with the
> >> camera relatively close to the subject and long focal length telephoto
> >> lenses tend to be used with the camera at relatively large distances,
> >> strong perspective is often associated with wide angle lenses and weak
> >> perspective is similarly associated with telephoto lenses, but it is

the
> >> camera position and not the focal length or type of lens that produces
> >> the abnormal linear perspective."

>
> >Obviously this is incorrect and even self-contradictory, isn't it?

>
> No, it's not. But they're using two slightly different meanings of
> perspective in the same paragraph.
>
> The wide angle photo shows much stronger perspective-related effects
> than the telephoto shot *when both are viewed with the same visual
> angle*.
>
> On the other hand, if both are viewed with the visual angle of the
> corresponding taking lens, there is no unnatural perspective at all.
>
> It's perfectly reasonable to say that the "wide angle perspective" is
> really the result of viewing the print from a greater distance,
> occupying a smaller visual angle, than is correct. Similarly, the
> "telephoto perspective" can be said to be the result of looking at the
> print from too small a distance, with too large a visual angle.
> This is just as true as saying the change in apparent perspective is due
> to the change in camera lens.
>
> So, if you assume a constant print size and viewing distance, you can
> change perspective by changing lens. If you also keep about the same
> amount of the in-focus object within the frame, you will have to change
> the camera-subject distance in proportion to the focal length. And when
> you do that, the change in apparent perspective is due to the camera
> position change - not the focal length change.
>
> On the other hand, depending on your assumptions about linear and
> angular field of view, and print size and viewing distance, all of the
> variables are tied together anyway. So it's a little bit untrue to say
> which one "causes" and which one is "caused by". The quote above is
> trying to tell you that just changing lenses *alone* will not change
> perspective, while moving the camera *alone* does change perspective.
> Both of these, however, also change the space that is included in the
> image.
>
> >Now to go on from that enlightened observation and then say that "it is

the
> >camera position and not the focal length or type of lens that produces

the
> >abnormal linear perspective" is clearly contradictory. If this were true,
> >then it would have to be possible to change THE CAMERA POSITION to one in
> >which it DOES NOT "produce the abnormal linear perspective." But you

cannot.
>
> Yes you can. If you assume a particular print size and viewing
> distance, that determines the focal length of lens *and camera position*
> that will give you a completely undistorted view.
>
> >A wide-angle lens will still produce the same "abnormal linear

perspective"
> >or "strong perspective" (as the article calls it) wherever you place the
> >camera, provided there are objects in the field of view to demonstrate

it;
>
> No, it does so as long as your viewing distance is such that the print
> occupies a smaller visual angle than the original scene. That's the
> only thing that's special about a wide-angle lens.
>
> >contrariwise, a telephoto lens will still produce its own kind of
> >perspective regardless of camera position.

>
> But whether it is absolutely correct, shows "telephoto distortion", or
> even "wideangle distortion" depends on viewing distance and print size.
>
> Dave



 
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mcgyverjones
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      08-08-2004

"Nostrobino" <(E-Mail Removed)> wrote in message
news:T%sRc.882$(E-Mail Removed). ..
>
> "mcgyverjones" <mcgyverjones(spamout)@hotmail.com> wrote in message
> news:0idRc.46212$(E-Mail Removed) ...
> >
> > "Nostrobino" <(E-Mail Removed)> wrote in message
> > news:uU7Rc.262$(E-Mail Removed).. .
> > snip
> > > There's a photographer who prefers very long
> > > lenses (e.g., 300mm on a 35) for shooting half-length pictures of

> > beautiful
> > > girls. He doesn't NEED a long focal length; the girls are models and

> will
> > be
> > > wherever he places them, but he likes the strong look that the spatial
> > > compression of a really long lens gives him.

> >
> > This is exactly where you are wrong. The tele lens does not give any

kind
> > of compression at all.
> > The apparent compression is purely a result of the camera position.
> > The lens simply allows the photographer to crop in camera without losing
> > resolution.

>
> He isn't "cropping" anything, any more than using a normal f.l. lens is
> "cropping" what WOULD have appeared in a wide-angle shot. He's using the
> 300mm lens because that is what gives him the perspective he wants. Does
> this also imply a more distant camera position? Obviously!
>

And it's the distance that provides the perspective, not the focal length.


 
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Anthony Ralph
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      08-08-2004
mcgyverjones wrote:
:: "Nostrobino" <(E-Mail Removed)> wrote in message
:: news:T%sRc.882$(E-Mail Removed). ..
:::

[...]

::: He isn't "cropping" anything, any more than using a normal f.l.
::: lens is "cropping" what WOULD have appeared in a wide-angle shot.
::: He's using the 300mm lens because that is what gives him the
::: perspective he wants. Does this also imply a more distant camera
::: position? Obviously!
:::
:: And it's the distance that provides the perspective, not the focal
:: length.

Surely he is using the 300mm lens to acheive the field of view he wants.
Perspective is a function of camera to object distance.

--
Regards:

Anthony Ralph
Buckingham UK
------------------------------------------
** Pull the CORK to reply**
------------------------------------------


 
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mcgyverjones
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      08-09-2004

"Anthony Ralph" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> mcgyverjones wrote:
> >:: "Nostrobino" <(E-Mail Removed)> wrote in message
> >:: news:T%sRc.882$(E-Mail Removed). ..

> :::
>
>> [...]

>
>> ::: He isn't "cropping" anything, any more than using a normal f.l.
>> ::: lens is "cropping" what WOULD have appeared in a wide-angle shot.
>> ::: He's using the 300mm lens because that is what gives him the
>> ::: perspective he wants. Does this also imply a more distant camera
> >::: position? Obviously!




> :: And it's the distance that provides the perspective, not the focal
> :: length.
>
> Surely he is using the 300mm lens to acheive the field of view he wants.
> Perspective is a function of camera to object distance.
>

Exactly. Now tell Nostrobino that (or beat your head against the wall).


 
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Nostrobino
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      08-09-2004

"Anthony Ralph" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> mcgyverjones wrote:
> :: "Nostrobino" <(E-Mail Removed)> wrote in message
> :: news:T%sRc.882$(E-Mail Removed). ..
> :::
>
> [...]
>
> ::: He isn't "cropping" anything, any more than using a normal f.l.
> ::: lens is "cropping" what WOULD have appeared in a wide-angle shot.
> ::: He's using the 300mm lens because that is what gives him the
> ::: perspective he wants. Does this also imply a more distant camera
> ::: position? Obviously!
> :::
> :: And it's the distance that provides the perspective, not the focal
> :: length.
>
> Surely he is using the 300mm lens to acheive the field of view he wants.


No, the perspective. Field of view is not what makes the shot look the way
he wants it to.The field of view is whatever goes with the perspective he
wants. They go together like bacon and eggs, but bacon is bacon and eggs are
eggs.


 
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Nostrobino
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      08-09-2004

"mcgyverjones" <mcgyverjones(spamout)@hotmail.com> wrote in message
news:iPCRc.6138$(E-Mail Removed).. .
>
> "Anthony Ralph" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > mcgyverjones wrote:
> > >:: "Nostrobino" <(E-Mail Removed)> wrote in message
> > >:: news:T%sRc.882$(E-Mail Removed). ..

> > :::
> >
> >> [...]

> >
> >> ::: He isn't "cropping" anything, any more than using a normal f.l.
> >> ::: lens is "cropping" what WOULD have appeared in a wide-angle shot.
> >> ::: He's using the 300mm lens because that is what gives him the
> >> ::: perspective he wants. Does this also imply a more distant camera
> > >::: position? Obviously!

>
>
>
> > :: And it's the distance that provides the perspective, not the focal
> > :: length.
> >
> > Surely he is using the 300mm lens to acheive the field of view he wants.
> > Perspective is a function of camera to object distance.
> >

> Exactly. Now tell Nostrobino that (or beat your head against the wall).


I am beginning seriously to doubt that half of you even know what
"perspective" means. (Other than "duhhhh, something to do with camera
position.")


 
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Anthony Ralph
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      08-09-2004
Nostrobino wrote:

[...]


:::::: And it's the distance that provides the perspective, not the
:::::: focal length.
::::
:::: Surely he is using the 300mm lens to acheive the field of view he
:::: wants. Perspective is a function of camera to object distance.
::::
::: Exactly. Now tell Nostrobino that (or beat your head against the
::: wall).
::
:: I am beginning seriously to doubt that half of you even know what
:: "perspective" means. (Other than "duhhhh, something to do with camera
:: position.")


Well... you can count me in the half that does know what it is. I also know what field of view is too.

--
Regards:

Anthony Ralph
Buckingham UK
------------------------------------------
** Pull the CORK to reply**
------------------------------------------
 
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Nostrobino
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      08-09-2004
And for WHICH of those would you say a photographer selects a 100mm lens (or whatever his choice is) for portraiture?

"Anthony Ralph" <(E-Mail Removed)> wrote in message news:(E-Mail Removed)...
Nostrobino wrote:

[...]


:::::: And it's the distance that provides the perspective, not the
:::::: focal length.
::::
:::: Surely he is using the 300mm lens to acheive the field of view he
:::: wants. Perspective is a function of camera to object distance.
::::
::: Exactly. Now tell Nostrobino that (or beat your head against the
::: wall).
::
:: I am beginning seriously to doubt that half of you even know what
:: "perspective" means. (Other than "duhhhh, something to do with camera
:: position.")


Well... you can count me in the half that does know what it is. I also know what field of view is too.

 
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